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Human Exposure and Atmospheric Sciences Division Publications: 2005

This page lists publication titles, citations and abstracts produced by NERL's Human Exposure and Atmospheric Sciences Division for the year 2005, organized by Publication Type. Your search has returned 154 Matching Entries.

See also Human Exposure and Atmospheric Sciences Division citations with abstracts: 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008

Technical Information Manager: Liz Hope - (919) 541-2785 or hope.elizabeth@epa.gov

		Presented/Published
BOOK CHAPTER	Persistent, Bioaccumulative, and Toxic Pollutants (Pbts)	01/06/2005

Vallero, D. A. Persistent, Bioaccumulative, and Toxic Pollutants (Pbts). 1.Chapter 3, McGraw-Hill 2005 Yearbook of Science & Technology. McGraw-Hill Professional, New York, NY, 252-257, (2005).
Abstract:	Article describes the class of compounds known as persistent, bioaccumulative, and toxic pollutants (known as PBTs), including the mechanisms responsible for ability to build up the food chain and for causing adverse health effects and ecosystem damage. Exposure to numerous PBTs have been associated with effects on the nervous system, endocrine dysfunction, reproductive and developmental problems, cancer, and genetic impacts. PBTs can travel long distances, moving among the "environmental compartments," i.e. biota, air, water, and land, and can persistent for decades, as evidenced by the polychlorinated biphenyls (PCBs) that are found in sediment, soil, water, and organic tissues several decades after these substances were banned. PBTs may be organic compounds like the PCBs or dioxins, as well as metallic compounds, such as those of mercury, chromium, lead, and cadmium.

BOOK CHAPTER	Persistent Organic Pollutants in Dusts That Settled at Indoor and Outdoor Locations in Lower Manhattan After 11 September, 2001	12/01/2005

Offenberg, J., S. Eisenreich, C. L. Gigliotti, L. C. Chen, M. D. Cohen, G. Chee, C. Prophete, J. Q. Xiong, C. Quan, X. Lou, M. Zhong, J. Gorezynski, L. Yiin, V. Illacqua, C. P. Weisel, AND P. J. Lioy. Persistent Organic Pollutants in Dusts That Settled at Indoor and Outdoor Locations in Lower Manhattan After 11 September, 2001. , Chapter 6, Urban Aerosols and Their Impacts . American Chemical Society, Washington, DC, 103-113, (2006).
Abstract:	During the initial days that followed the explosion and collapse of the World Trade Center (WTC) on September 11th, 2001, fourteen bulk samples of settled dusts were collected at locations surrounding the epicenter of the disaster, and analyzed for persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and select organo-chlorine pesticides on settled dust samples. The sigma 86-PCBs comprised less than 0.001% by mass of the bulk in three bulk outdoor samples analyzed, indicating that PCBs were of limited significance in the total settled dust across lower Manhattan. Likewise, organo-chlorine pesticides, including Chlordanes, Hexachlorobenzene, Heptachlor, 4,4'-DDE, 2,4'-DDT, 4,4'-DDT and Mirex were found at low concentrations in the bulk samples. Conversely, the sigma 37-PAHs comprised up to nearly 0.04% (<0.005 to 0.039%) by mass of the bulk settled outdoor dust in the six bulk samples. Further size segregation of three initial bulk samples and seven additional samples indicates that sigma 37-PAHs were found in higher concentrations on relatively large particles (10-53 µm), representing up to 0.04% of the total dust mass. Significant concentrations were also found on fine particles (<2.5 µm), often accounting for ~0.005 % by mass. In addition to these outdoor dusts, twelve bulk samples of the settled dust were collected at indoor locations surrounding the epicenter of the disaster, including one sample from a residence that had been cleansed and was once again occupied. Concentrations of sigma 86-PCBs comprised less than one part per million by mass of the bulk in the two indoor dusts samples analyzed, indicating that PCBs were of limited significance in the dust that settled at indoor locations across lower Manhattan. Likewise, organo-chlorine pesticides, Hexachlorobenzene, Heptachlor, 4,4'-DDE, 2,4'-DDT, 4,4'-DDT and Mirex were found at even lower concentrations in the bulk samples. Conversely, sigma 37-PAHs comprised up to 0.04% (<0.005 to 0.036%) by mass of the bulk indoor dust in the eleven WTC impacted bulk indoor samples. In addition to similar concentrations, comparison of PAH concentration patterns (i.e. chemical fingerprints) shows that dusts that settled indoors are chemically similar to previously measured WTC dusts found at outdoor locations. Analysis of one sample of indoor dusts collected from a vacuum cleaner of a rehabilitated home shows markedly lower PAH concentrations (< 0.0005 mass %), as well as differing relative contributions for individual compounds. These PAH analyses may be used in identifying dusts of WTC origin at indoor locations, along with ascertaining further needs for cleaning. The United States Environmental Protection Agency through its Office of Research and Development partially funded the research described here. This work has been subjected to peer-review and has been cleared for publication.

BOOK CHAPTER	Recent Developments in Exhaled Breath Analysis and Human Exposure Research	05/01/2005

LINDSTROM, A. B. Recent Developments in Exhaled Breath Analysis and Human Exposure Research. , Chapter 23, Anton Amann, David Smith (ed.), Breath Gas Analysis for Medical Diagnostics. World Scientific Publishing Co. Pte. Ltd., 5 Toh Tuck Link, Singapore, 337-346, (2005).
Abstract:	Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that unlike blood, breath collection is noninvasive and generally well tolerated by study subjects. This research has focused on demonstrating exposures to volatile compounds, establishing conclusive links between specific activities and corresponding body burdens of xenobiotics, characterizing uptake and elimination kinetics, and illuminating relevant pathways of exposure. In the past few years exhaled breath analysis has evolved to the point where it is now being used to help characterize biological responses associated with exposures to environmental pollutants. This paper explores historical and newly emerging methods for the collection and analysis of exhaled breath for use in environmental exposure assessment studies. It discusses their applicability and limitations with respect to environmental research. Particular emphasis is placed on new methods and their utility for examining exhaled biomarkers of environmental pollution. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

BOOK CHAPTER	The Unique Value of Breath Biomarkers for Estimating Pharmacokinetic Rate Constants and Body Burden from Environmental Exposures	05/01/2005

PLEIL, J. D., D. KIM, J. D. PRAH, D. ASHLEY, AND S. RAPPAPORT. The Unique Value of Breath Biomarkers for Estimating Pharmacokinetic Rate Constants and Body Burden from Environmental Exposures. , Chapter 24, Anton Amann and David Smith (ed.), Breath Analysis for Clinical Diagnosis and Therapeutic Monitoring. World Scientific Publishing Co. Pte. Ltd., 5 Toh Tuck Link, Singapore, 347-359, (2005).
Abstract:	Although detection of breath odor is the oldest of the medical diagnostic techniques, blood and urine biomarker measurements are the current "gold standard" for modern exposure and health assessments. Of late, it has been recognized that collecting exhaled breath is an attractive alternative to blood and urine sampling because it is less invasive and is not restricted by sample volume or time frame. In this work, we use a simple classical pharmacokinetic (PK) model and explore the utility of breath measurement for assessing uptake, metabolism, and elimination of an exogenous chemical. We demonstrate the unique value of breath biomarkers as a complementary measurement to blood biomarkers using results from previous study of controlled human exposures to methyl tertiary butyl ether (MTBE) and the production of the primary first order metabolite tertiary butyl alcohol (TBA). We estimate initial 72% alveolar uptake efficiency from inhalation exposure of MTBE and a steady state conversion of 68% of MTBE body burden to TBA corresponding to 0.385/hr and 0.818/hr rate constants, respectively. Only 0.53% of TBA body burden is eliminated via breath, the remainder is excreted or metabolized with a rate constant of 0.0565/hr. We further demonstrate that the temporal concentration profiles of breath and blood biomarkers are similar in character and that they result in consistent estimates of average dose from external sources. We estimate steady-state blood/breath ratios for MTBE and TBA as 16.9 and 797 and hypothetical volumes of distribution as 86 l and 175 l, respectively. Finally, we attribute to pulmonary metabolism about 0.8% of MTBE to TBA conversion from inhalation exposure. The United States Environmental Protection Agency through its Office of Research and Development funded the research described here. It has been subjected to Agency review and approved for publication.

DATA	Supersites Integrated Relational Database (Sird)	08/17/2005

ONDOV, J. M. AND D. ONDOV. Supersites Integrated Relational Database (Sird). University of Maryland Biotechnology Institute, College Park, MD, 2005.
Abstract:	As part of EPA's Particulate Matter (PM) Supersites Program (Program), the University of Maryland designed and developed the Supersites Integrated Relational Database (SIRD). Measurement data in SIRD include comprehensive air quality data from the 7 Supersite program locations for the time period June 2001 to August 2002. The public availability of this database will allow states and regions to better model PM air pollution on local and regional scales and the US EPA on national scales. The database can be found at the Supersites Data Website: http://supersitesdata.umd.edu/ .

DATA	Stochastic Human Exposure and Dose Simulation Model for Particulate Matter (Sheds-PM) Version 2.1	09/09/2005

BURKE, J. M. Stochastic Human Exposure and Dose Simulation Model for Particulate Matter (Sheds-PM) Version 2.1. U.S. Environmental Protection Agency, Washington, DC, EPA/600/C-05/012, 2005.
Abstract:	The SHEDS-PM 2.1 model is an executable (no software requirement) with a user-friendly interface for predicting population distributions of exposure and dose for PM and its constituents. The model estimates the distribution of total and ambient PM exposures for a user-specified population of interest based on user-provided ambient PM concentration data (hourly- or daily-averaged concentration data).

ETV DOCUMENT	An Environmental Technology Verification (Etv) Performance Testing of the Industrial Test System, Inc. Cyanide Reagentstrip™ Test Kit	05/11/2005

BATTELLE MEMORIAL INSTITUTE. An Environmental Technology Verification (Etv) Performance Testing of the Industrial Test System, Inc. Cyanide Reagentstrip™ Test Kit. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/059 (NTIS PB2006-101290), 2005.
Abstract:	Cyanide can be present in various forms in water. The cyanide test kit evaluated in this verification study (Industrial Test System, Inc. Cyanide Regent Strip ™ Test Kit) was designed to detect free cyanide in water. This is done by converting cyanide in water to cyanogens chloride, which, in the presence of isonicotinic and babituric acids, produces a color change that can be detected visually or with a colorimeter. Vendor suggested colorimetric analytical methods are dependent upon the data needs of the user.

ETV DOCUMENT	An Environmental Technology Verification (Etv) Testing of Two Hydrogen Sulfide Analyzers: Horiba Instruments, Inc., Apsa-360 and Teledyne-Api Model 101e	09/19/2005

BATTELLE MEMORIAL INSTITUTE, A. L. SUMNER, A. DINDAL, Z. WILLENGERG, AND K. RIGGS. An Environmental Technology Verification (Etv) Testing of Two Hydrogen Sulfide Analyzers: Horiba Instruments, Inc., Apsa-360 and Teledyne-Api Model 101e. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/126 (NTIS PB2006-101284), 2005.
Abstract:	The Environmental Technology Verification (ETV) Program, beginning as an initiative of the U.S. Environmental Protection Agency (EPA) in 1995, verifies the performance of commercially available, innovative technologies that can be used to measure environmental quality. The ETV provides, through a third-party, quality-assured performance data so buyers and users of environmental technologies can make informed purchase and application decisions, thus providing one path to reducing emissions and improving human health. To provide cost-effective testing, Stakeholder committees, made up of members with diverse backgrounds, provide guidance with identifying and prioritizing environmental technologies to address present day environmental quality challenges. The ETV Advanced Monitoring Systems (AMS) Center, one of six ETV Centers, is actively involved in verifying the performance of advanced monitoring systems available to the public for purchase. The AMS Center participates in the mission of the ETV by providing Test Plans, Protocols, conducting independent performance tests of technologies, and preparing Verification Reports and Statements describing the results of the testing. Vendors of tested technologies can use the Verification Reports and Statements for marketing purposes. All approved Verification Reports are posted on the ETV Web Site as a form of public distribution. The individual verification reports and statements describe by this abstract are fora Horiba Instruments, Inc. Model APSA-360 and a Teledyne-API Model 101E ambient hydrogen sulfide analyzers. The objective of this verification test was to evaluate each analyzer's performance in measuring gaseous H2S in ambient air at an animal feeding operation (AFO). The verification test was conducted for six weeks between April 25 and June 3, 2005, at a swine finishing farm near Ames, Iowa. This site was selected to provide realistic testing conditions and was expected to exhibit a wide range of H2S concentrations during the test period. The verification test was designed to evaluate accuracy, bias, precision, linearity, span and zero drift, response time, interference effects, comparability, data completeness, and operational factors. The analyzer's response to a series of H2S gas standards was used to evaluate accuracy, bias, precision, and linearity. Each gas standard was delivered in triplicate, and the series of gas standards were delivered three times during the verification test. Accuracy was calculated at each concentration and for each replicate relative to the nominal H2S concentration. Bias was calculated for each series of multipoint H2S challenges. Precision was demonstrated by the reproducibility of the analyzer's response at each nominal H2S concentration. Linearity was assessed by establishing a multipoint calibration curve from each analyzer's response. The baseline response of each analyzer to zero air and a 30-parts per billion (ppb) dilution of a compressed H2S gas standard was determined during the first week of testing. At least twice each week, zero air and a 30-ppb H2S standard again were supplied to the analyzer for 20 minutes for a total of 14 zero/span checks. Each response was compared to the Week 1 baseline response to determine whether drift occurred in the response to zero air or the 30-ppb H2S standard. The data collected during the two zero/span baseline response checks were used to determine the analyzer's response time. To determine interference effects, each analyzer was challenged with a series of gases (supplied at either 100 or 500 ppb in the presence and absence of 100 ppb of H2S) that may be present at an AFO and could interfere with the analyzer's response to H2S. The comparability of each analyzer's response to ambient air was evaluated by comparing its response to two H2S reference methods (time-integrated and in situ), which were carried out by the U.S. Department of Agriculture (USDA) and Applied Measurement Science. The two reference methods were based on American Society of Testing Materials (ASTM) Method D5504-01, with pulsed flame photometric detection substituted for sulfur chemiluminescence detection. Data completeness was assessed based on the overall data return achieved by each analyzer. Operational factors such as maintenance needs, data output, consumables used, ease of use, and repair requirements were evaluated based on the observations of Battelle and USDA staff. QA oversight of the verification testing was provided by the EPA and Battelle. Battelle QA staff conducted a technical systems audit and a data quality audit of 10% of the test data. The verification statement, the full report on which it is based, and the test/QA plan for this verification are all available at http://www.epa.gov/etv/centers/center1.html.

ETV DOCUMENT	An Environmental Technology Verification (Etv) Testing of Two Nutrient Analyzers at An Industrial Plant: Schimadzu Scientific Instruments, Inc. Tnpc-4110(c) and a Zaps Technologies, Inc. Multi-Parameter (Mp-1)	09/29/2005

BATTELLE MEMORIAL INSTITUTE, A. L. SUMNER, A. DINDAL, Z. WILLENBERG, K. RIGGS, W. L. SMITH, AND K. N. WOOD. An Environmental Technology Verification (Etv) Testing of Two Nutrient Analyzers at An Industrial Plant: Schimadzu Scientific Instruments, Inc. Tnpc-4110(c) and a Zaps Technologies, Inc. Multi-Parameter (Mp-1). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/125 (NTIS PB2006-101289), 2005.
Abstract:	The Environmental Technology Verification (ETV) Program, beginning as an initiative of the U.S. Environmental Protection Agency (EPA) in 1995, verifies the performance of commercially available, innovative technologies that can be used to measure environmental quality. The ETV provides, through a third-party, quality-assured performance data so buyers and users of environmental technologies can make informed purchase and application decisions, thus providing one path to reducing emissions there by improving the quality of the environment and reducing health risk to humans. To provide cost-effective testing, Stakeholder committees, made up of members with diverse backgrounds, provide guidance with identifying and prioritizing environmental technologies to address present day environmental quality challenges. The ETV Advanced Monitoring Systems (AMS) Center, one of six ETV Centers, is actively involved in verifying the performance of advanced monitoring systems available to the public for purchase. The AMS Center participates in the mission of the ETV by providing Test Plans, Protocols, conducting independent performance tests of technologies, and preparing Verification Reports and Statements describing the results of the testing. Vendors of tested technologies can use the Verification Reports and Statements for marketing purposes. All approved Verification Reports are posted on the ETV Web Site as a form of public distribution. The individual verification reports and statements describe by this abstract are the Schimadzu Scientific Instruments, Inc. TNPC-4110(C) and the ZAPS Technologies, Inc. Multi-Parameter (MP-1) Nutrient Analyzers. The objective of this verification test was to evaluate the analyzers' performance in quantifying nutrient concentrations in wastewater at an industrial wastewater treatment plant. The verification test was conducted between May 5 and June 16, 2005, at the DuPont Company's industrial wastewater treatment facility at the Spruance Plant in Richmond, Virginia. At the Spruance Plant, DuPont manufactures engineering polymers/plastics and fibers (e.g., NOMEX flame retardant and KEVLAR). Operations Management International (OMI), Inc., operates the wastewater treatment plant under contract with DuPont. The wastewater from the Spruance Plant provided a single example of possible matrix effects associated with wastewater monitoring. The verification test was designed to evaluate accuracy, bias, linearity, limit of detection (LOD), reproducibility, span and zero drift, interference effects, matrix effects, data completeness, and operational factors. The test had two components: off-line testing (two phases) and on-line effluent monitoring. During off-line Phase I testing, the analyzers were challenged with multi-level nutrient standards and deionized (DI) water to determine their accuracy, bias, linearity, and LOD. The analyzers were challenged with additional nutrient standards for the determination of interference effects for several forms of nitrogen and phosphorous. Reproducibility was evaluated during off-line Phase I testing by repeatedly challenging the analyzers with a mixed standard containing potassium nitrate and potassium dihydrogenphosphate. To determine span and zero drift, once each week, DI water and the mixed nutrient standard were supplied to the analyzers for a total of five zero/span checks. During off-line Phase I and Phase II testing, the analyzers were challenged with a series of samples containing altered DI water or wastewater matrices to determine matrix effects. During on-line effluent monitoring, analyzer matrix effects were evaluated for the final effluent. Data completeness was assessed based on the overall data return, and operational factors were evaluated based on the observations of Battelle and OMI staff. QA oversight of the verification testing was provided by the EPA and Battelle. Battelle QA staff conducted a technical systems audit and a data quality audit of 10% of the test data. The verification statement, the full report on which it is based, and the test/QA plan for this verification are all available at http://www.epa.gov/etv/centers/center1.html.

EXTRAMURAL DOCUMENT	Dermal Exposure to Methyl Tert-Butyl Ether (Mtbe) and Dibromochloromethane (Dbcm) While Bathing With Contaminated Water	03/17/2005

GORDON, S. M. Dermal Exposure to Methyl Tert-Butyl Ether (Mtbe) and Dibromochloromethane (Dbcm) While Bathing With Contaminated Water. U.S. Environmental Protection Agency, Washington, DC, 2005.
Abstract:	The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced hazardous air pollutants, the increasing occurrence and detection of MTBE in drinking water sources in California, New Jersey, and elsewhere has raised concerns about potential exposures from water usage and resulting health effects. In addition to MTBE, disinfection byproducts can be present in the water people use for showering, bathing, or drinking, as a result of the reaction of disinfection agents with organic material already present in water. Chlorine, a widely used disinfection agent, reacts with humic acids to form the trihalomethanes, which are the most common and abundant byproducts in chlorinated water. Besides chloroform, which has been extensively studied, the byproduct dibromochloromethane (DBCM) occurs as a result of the chlorination process in those areas that naturally have bromide in their ground water. Because the breath analyzer showed almost no discernible change in MTBE and DBCM breath concentrations in the shower experiments that were conducted, we abandoned all further shower exposure efforts in favor of the bath water experiments. Three male and two female volunteers participated in the bath water study, in which each was exposed to 40 µg/L of DBCM and 150 µg/L of MTBE-d₁₂ in water for 30 minutes. We were unable to derive meaningful results from the real-time breath analyzer data generated for DBCM, largely because of what appeared to be an interfering contaminant with mass spectral fragment ions that occurred at the same mass as the mass used to monitor for DBCM. All of the breath concentration/time profiles obtained for the five participants, as a result of dermal exposure to MTBE-d₁₂ and MTBE in water, showed similar small increases in breath concentrations, from levels that were roughly equal to or less than 2 - 10 µ/m³, the method detection limit, to peak levels of 7 - 15 µg/m³. After exposure ended, breath levels slowly decreased and tended toward the pre-exposure levels during the 30-minute elimination monitoring period. In all cases, except for one subject, the measured levels throughout the monitoring periods were above the limits of detection obtained with the real-time breath analyzer. This concentration range is similar to that reported for background levels of MTBE in previous studies that relied on batch collection and gas chromatographic/mass spectrometric (GC/MS) analysis for breath sample measurement. Uptake and elimination residence times were estimated using a one-compartment linear model. The mean residence times for the decay phase were roughly twice as long as the mean residence times for the uptake phase, viz., _Tuptake = 21.2 ± 13.1 min and _Tdecay = 41.5 ± 26.3 min [mean 1 standard deviation]. The reasonably good agreement obtained for the residence times among the five participants suggests that our estimates of the model parameters may be fairly robust. These estimated values are much greater than the residence times obtained in our earlier study of the dermal absorption of chloroform from bath water, for which the mean uptake residence time was 8.2 ± 3.1 min and the mean decay residence time was 7.7 ± 1.0 min. This may be due to the greater solubility of MTBE in water, which is reflected by their respective Henry's Law coefficients, namely, 1.6 mole/atm for MTBE vs. 0.26 mole/atm for chloroform. These residence times also are significantly larger than the uptake and decay residence times for MTBE determined in our companion inhalation study. The total amount of MTBE-d₁₂ exhaled during the exposure and post-exposure periods was estimated by integrating the area under the breath uptake and elimination curve. The mean amount of MTBE-d₁₂ exhaled at an average temperature of 39.5 ^°C was 3.0 ± 1.1 (SD) µg (range: 1.7 - 4.6 µg). The mean exhaled amount obtained in our earlier bath water study of chloroform absorption at roughly the same temperature was 7.0 ± 2.0 µg. This indicates that the dermal uptake of MTBE from bath water is significantly smaller than that of chloroform under similar exposure conditions. It is interesting to note that, although dermal absorption of MTBE from water has been measured directly in the blood of human subjects in at least one earlier study, our measurements appear to be the first of the dermal uptake of MTBE using continuous breath analysis. Finally, the model parameters determined in this study may be useful to risk assessors in EPA State and Regional offices for estimating dermal exposure to this contaminant while bathing.

EXTRAMURAL DOCUMENT	Report on Geographic and Seasonal Variability of UV Affecting Human and Ecological Health	05/09/2005

WEATHERHEAD, E. C. Report on Geographic and Seasonal Variability of UV Affecting Human and Ecological Health. Global Environmental Engineering Consultants,Inc., Lafayette, CO, 2005.
Abstract:	This report takes a look at how effects of ultraviolet radiation changes based on season and location. The data collected by EPA's network of Brewer Spectrophotometer devices was analyzed to determine trends in the flux of ultraviolet radiation at the different Brewer sites across the United States.

EXTRAMURAL DOCUMENT	Inhalation Exposure to Methyl Tert-Butyl Ether (Mtbe) and Dibromochloromethane (Dbcm) Using Continuous Breath Analysis	03/17/2005

GORDON, S. M. Inhalation Exposure to Methyl Tert-Butyl Ether (Mtbe) and Dibromochloromethane (Dbcm) Using Continuous Breath Analysis. U.S. Environmental Protection Agency, Washington, DC, 2005.
Abstract:	The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced hazardous air pollutants, the increasing occurrence and detection of MTBE in drinking water sources in California, New Jersey, and elsewhere has raised concerns about potential exposures from water usage and resulting health effects. In addition to MTBE, disinfection byproducts can be present in the water people use for showering, bathing, or drinking, as a result of the reaction of disinfection agents with organic material already present in water. Chlorine reacts with humic acids to form the trihalomethanes, which are the most common and abundant byproducts in chlorinated water. Besides chloroform, which has been widely studied, the byproduct dibromochloromethane (DBCM) occurs as a result of the chlorination process in those areas that naturally have bromide in their ground water. Relatively little information on exposure to this chemical is available. This study was designed to determine the uptake by humans of MTBE and DBCM as a result of controlled, short-term inhalation exposures. Our approach made use of continuous real-time breath analysis to generate exhaled-breath profiles, and evaluate MTBE and DBCM kinetics in the body. Seven subjects were exposed continuously via face mask to 2,217 µg/m³ (542 ppbv) MTBE-d₁₂ and 728 µg/m³ (85.6 ppbv) DBCM, except for several brief (~2-min) intervals during which breath measurements were taken. Total exposure time was ~30 min, followed by exposure to clean air for a further 30-60 min. Exhaled breath was sampled and analyzed with the real-time breath technology; blood samples were simultaneously collected from the subjects (3-4 samples during exposure; 2-5 samples post-exposure). The real-time technology was specially modified with a biofeedback exposure control system to allow us to make uptake measurements during the exposure period; breath measurements were taken continuously throughout the post-exposure period. The exposures resulted in an increase in the measured breath concentration of MTBE-d₁₂ from levels that were less than 10 - 20 µg/m³ (2 - 5 ppbv), the method detection limit, to 200 - 450 µg/m³ (50 - 110 ppbv) following exposure. MTBE-d₁₂ blood concentrations increased from the limit of detection, 0.30 µg/L, to ~0.9 - 2.5 µg/L at the end of the ~30-min exposure period. The time-course measurements of both exhaled breath and venous blood are well-described by the linear compartmental uptake and elimination models, the interpretation of which provides important information on the residence times of the compound in the body, the relative capacity of each compartment, and the fraction of the chemical exhaled unchanged at equilibrium. The breath uptake data were consistent with a one-compartment model. The mean value for the one-compartment uptake residence times T_1uptake was 5.7 ± 2.4 (SD) min (range 3.3 - 9.8 min). In contrast, the breath decay phase data gave satisfactory two-compartment fits. The mean value for the first compartment decay residence times T_1decay was 3.8 ± 1.9 (SD) min (range 2.4 - 7.8 min); for the second compartment, the mean decay residence time T_2decay was 61 ± 11 (SD) min (range 46 - 73 min). The blood uptake data were also consistent with a one-compartment model and were convergent in almost all cases. The average blood uptake residence time was essentially the same as that for the breath. The quality of the blood decay data were such that we were only able to extract meaningful information from 2 or 3 data sets. The mean MTBE-d₁₂ total absorbed ("internal") dose was 149 ± 34 µg for the average 30-min exposure and a mean total ("applied") dose of 209 µg. The mean fraction of MTBE-d₁₂ absorbed, or relative uptake, was 0.73 ± 0.04. The mean value for ƒ, the fraction of the MTBE-d₁₂ exposure concentration exhaled unchanged was 0.29 ± 0.04. This value is in good agreement with the value recently reported by Lee et al. Using linear regression analysis, the mean blood/breath ratio for MTBE-d₁₂ was found to be 6.7 ± 3.4. This value is significantly lower than values obtained in previous studies. The reason for this discrepancy is not clear. By and large, background levels for DBCM in the exhaled breath were below the limit of detection, and the signal measured for this compound at m/z 129, the most abundant ion in the glow discharge mass spectrum, was exceptionally "noisy". The average signals during the uptake phase provided initial (pre-exposure) breath concentration values that ranged from 70 to 160 µg/m³ and rose to between 130 and 250 µg/m³ after 30 minutes. The high initial breath concentrations suggest that the measured signal at m/z 129 was probably elevated due to an unknown contaminant with fragment ions at the same mass. For tert-butyl alcohol (TBA), all of the blood measurements were below the detection limit.

JOURNAL	Cancer Incidence in the Agricultural Health Study	10/01/2005

Alavanja, M., D. P. Sandler, C. Lynch, C. Knott, J. H. Lubin, R. Tarone, K. W. Thomas, M. Dosemeci, J. Barker, J. A. Hoppin, AND A. Blair. Cancer Incidence in the Agricultural Health Study. SCANDINAVIAN JOURNAL OF WORK, ENVIRONMENT, AND HEALTH. Scandinavian Journal of Work Environment, Helsinki, Finland, 31(Supp1):39-45, (2004).
Abstract:	The Agricultural Health Study (AHS) was undertaken to ascertain the etiology of cancers observed to be elevated in agricultural populations. Methods: The AHS is a large prospective, cohort study of private applicators and commercial applicators licensed to apply restricted use pesticides, and the spouses of farmer applicators from Iowa and North Carolina, USA. Cohort members were matched to cancer registry files in Iowa and North Carolina, and to the National Death Index (NDI) to ascertain vital status. Incident cases were identified from enrollment through December 31, 2000. Standardized Incidence Ratios (SIRs) were used to compare the cancer incidence experience of cohort members to the total population of Iowa and North Carolina. Results: The overall cancer incidence among farmers (SIR=0.80, 0.76-0.84) and the spouses of farmers (SIR=0.83, 95% CI=0.77-0.89) are significantly lower than that expected, particularly for respiratory and urinary cancers. The overall cancer incidence of commercial pesticide applicators is comparable to the expected (SIR= 1.01, 95% CI=0.81-1.24). Smoking prevalence in this population is significantly lower than the national average. Prostate cancer was elevated among private applicators (SIR=1.16, 1.07-1.25) and among commercial applicators (SIR=1.29, 0.84-1.89). An excess risk of ovarian cancer was observed in female applicators in Iowa (SIR=3.99, 0.80-11.66) and North Carolina (SIR=3.86, 1.24-9.00), but not among the female spouses (SIR=0.66, 0.43-0.96). Female spouses were observed to have a significant excess of melanoma (SIR=1.45, 1.05-1.97) that is not observed among pesticide applicators. Conclusions: Low overall cancer incidence rates seemed to be a result of low overall smoking prevalence and other lifestyle factors, while excess cancer of the prostate and ovaries among applicators may be occupationally related. The excess risk of melanoma observed among spouses was unexpected. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under Contracts 68-D99-011 to Battelle Memorial Institute and 68-D99-012 to RTI International and through Interagency Agreement DW-75-93912801-0 to the National Cancer Institute. It has been subjected to Agency review and approved for publication.

JOURNAL	Factors in Geotropospheric Particle-Gas Transport of Semivolatile Organic Compounds	01/01/2005

Vallero, D. A. Factors in Geotropospheric Particle-Gas Transport of Semivolatile Organic Compounds. ENVIRONMENTAL ENGINEERING SCIENCE. Mary Ann Liebert, Inc., Larchmont, NY, 22(1):109-125, (2005).
Abstract:	Semivolatile organic compounds (SVOCs) can exist in solid, liquid, or gas phases under ambient environmental conditions. The geotropospheric transport of SVOCs varies according to the particle type. Two classes of SVOCs and two types of particles were analyzed to determine possible transport mechanisms to the troposphere: dicarboximide compounds moving from a soil matrix to the troposphere and polycyclic aromatic hydrocarbons (PAHs) from airborne particles to the troposphere. Both classes of compounds are considered to be SVOCs since their vapor pressures under most environmental conditions range between 10-2 to 10-5 kP. The dicarboximide results were obtained from a laboratory chamber designed and used to determine the headspace flux of the dicarboximide fungicide, vinclozolin (3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-oxzoli-dine-2,4-dione), and its three principal degradation products from chamber surfaces, sand, and sterilized and non-sterile North Carolina Piedmont aquic hapludult soils following dicarboximide applications. The PAH results were gathered from a high-volume air sampling system used to measure particle and gas phase concentrations of SVOCs in the plume downwind from the World Trade Center fire. The comparison indicates that SVOC transport from the soil matrix can be influenced by the type and size of particles, their chemical composition, pH, oxygen, and microbial action. The study indicates that in the troposphere, molecular weight and structure are the principal factors affecting the geotropospheric flux of SVOCs from the particle to gas phase. Although experimentally determined equilibrium constants are more robust predictors of phase distribution in the troposphere (r2 = 0.81), published Henry's Law and vapor pressure constants also relate to particle-gas phase distribution (r2 = 0.73 and 0.72, respectively). This work has been funded in part by EPA. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

JOURNAL	Criteria and Air Toxic Emissions from in-Use, Low Emission Vehicles (Levs)	09/01/2005

Baldauf, R. W., W. Crews, R. Snow, J. R. Cook, AND P. A. Gabele. Criteria and Air Toxic Emissions from in-Use, Low Emission Vehicles (Levs). JOURNAL OF AIR & WASTE MANAGEMENT ASSOCIATION. Air & Waste Management Association, Pittsburgh, PA, 55(9):1263-1268, (2005).
Abstract:	The U.S. Environmental Protection Agency implemented a program to identify tailpipe emissions of criteria and air toxic contaminants from in-use, light-duty Low Emission Vehicles (LEVs). EPA recruited twenty-five LEVs in 2002, and measured emissions on a chassis dynamometer using the cold-start Urban Dynamometer Driving Schedule (UDDS) of the Federal Test Procedure (FTP). The emissions measured included regulated pollutants, particulate matter, speciated hydrocarbon compounds, and carbonyl compounds. The results provided a comparison of emissions from real world LEVs with emission standards for criteria and air toxic compounds. Emission measurements indicated that a portion of the in-use fleet tested exceeded standards for the criteria gases. Real-time regulated and speciated hydrocarbon measurements demonstrated that the majority of emissions occurred during the initial phases of the cold start portion of the UDDS. Overall, the study provided updated emission factor data for real world, in-use operation of LEVs for improved emissions modeling and mobile source inventory development. The United States Environmental Protection Agency, through its Office of Research and Development, funded and managed the research described in this manuscript. It has been subject to Agency review, and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation of use.

JOURNAL	Mortality Among Participants in the Agricultural Health Study	04/01/2005

Blair, A., D. P. Sandler, R. Tarone, J. Lubin, K. W. Thomas, J. A. Hoppin, C. Samanic, J. Coble, F. Kamel, C. Knott, M. Dosemeci, S. H. Zahm, C. Lynch, N. Rothman, AND M. Alavanja. Mortality Among Participants in the Agricultural Health Study. ANNALS OF EPIDEMIOLOGY. Elsevier Science Ltd, New York, NY, 15(4):279-285, (2004).
Abstract:	Purpose: This analysis of the Agricultural Health Study cohort assesses the mortality experience of licensed pesticide applicators and their spouses. Methods: This report is based on 52,393 private applicators (who are mostly farmers) and 32,345 spouses of farmers in Iowa and North Carolina. At enrollment, each pesticide applicator completed a 21-page enrollment questionnaire. Mortality assessment from enrollment (1994 to 1997) through 2000 provided an average follow-up of about 5.3 years, 447,154 person-years, and 2,055 deaths. Results: Compared to the general population in the two states, the cohort experienced a very low mortality rate. Standardized mortality ratios (SMRs) for total mortality, cardiovascular disease, diabetes, COPD, total cancer, and cancers of the esophagus, stomach, and lung were 0.6 or lower for both farmers and spouses. These deficits varied little by farm size, type of crops or livestock on the farm, years of handling pesticides, holding a non-farm job, or length of follow up. SMRs among ever smokers were not as low as among never smokers, but were still less than 1.0 for all smoking-related causes of death. No statistically significant excesses occurred, but slightly elevated SMRs, or those near 1.0, were noted for diseases that have been associated with farming in previous studies. Conclusions: Several factors may contribute to the low mortality observed in this population, including the healthy worker effect typically seen in cohorts of working populations (which may decline in future years), a short follow-up interval and a healthier lifestyle manifested through lower cigarette use and an occupation that has traditionally required high levels of physical activity. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under Contracts 68-D99-011 to Battelle Memorial Institute and 68-D99-012 to RTI International; and by Interagency Agreement DW-75-93912801-0 to the National Cancer Institute. It has been subjected to Agency review and approved for publication.

JOURNAL	Immunoassay Methods for Measuring Atrazine and 3,5,6-Trichloro-2-Pyridinol in Foods	11/01/2005

Van Emon, J. M. AND J. C. Chuang. Immunoassay Methods for Measuring Atrazine and 3,5,6-Trichloro-2-Pyridinol in Foods. Methods in Biotechnology. Humana Press Incorporated, Totowa, NJ, 19:231-238, (2006).
Abstract:	This chapter describes the use of enzyme-linked immunosorbent assay (ELISA) methods for the analysis of two potential environmental contaminants in food sample media, atrazine and 3,5,6-trichloro-2-pyridinol (3,5,6-TCP). Two different immunoassay formats are employed: a magnetic-particle immunoassay testing kit and a 96-microwell plate immunoassay. Diluted, filtered, nonfat baby foods were analyzed directly by a commercial magnetic-particle immunoassay testing kit for the determination of atrazine. Fatty baby foods were extracted with water for the magnetic-particle immunoassay analysis of obtrusion. For 3,5,6-TCP analysis, the food samples from a duplicate diet exposure study were analyzed by a laboratory-based 96-micro well plate immunoassay. Acidic methanol (72% methanol, 26% water, and 2% acetic acid) was the solvent for the food samples. The United States Environmental Protection agency (EPA) through its Office of Research and Development funded and collaborated in the research described here under contract No.68-D-99-011 to Battelle. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation by the EPA for use.

JOURNAL	Quantification of 2,4-D on Solid-Phase Exposure Sampling Media By LC/MS/MS	04/01/2005

Gardner, M., M. SpruillMcComb, J. Beach, L. Michael, K. W. Thomas, AND R. Helburn. Quantification of 2,4-D on Solid-Phase Exposure Sampling Media By LC/MS/MS. JOURNAL OF ANALYTICAL TOXICOLOGY. Preston Publications Incorporated, Niles, IL, 29(3):188-192, (2005).
Abstract:	Three types of solid phase chemical exposure sampling media: cellulose, polyurethane foam (PUF) and XAD-2, were analyzed for 2,4-D and the amine salts of 2,4-D. Individual samples were extracted into acidified methanol and the extracts were analyzed via LC/MS/MS using electrospray ionization and a C8 reversed-phase LC column. 13C 2,4-D and a labeled benzoic acid (13C or d5) were employed as the surrogate and internal standard respectively. Over a three year study of pesticide exposure among agricultural workers involving a high volume of analyses, values of average % recovery for 13C 2,4-D on personal exposure samples ranged from 87 to 98 with a % RSD ranging from 7 to 12. The performance of the method compares favorably with that of the current NIOSH recommended approach for the analysis of 2,4-D on these types of exposure sampling matrices. The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here under Contract 68-D-99-012 to RTI International. It has been subjected to Agency review, and approved for publication.

JOURNAL	Contributions of Children's Activities to Pesticide Hand Loadings Following Residential Pesticide Application	01/01/2005

FREEMAN, N. C., P. HORE, K. BLACK, M. JIMENEZ, L. S. SHELDON, N. S. TULVE, AND P. J. LIOY. Contributions of Children's Activities to Pesticide Hand Loadings Following Residential Pesticide Application. JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY. Nature Publishing Group, London, Uk, 15(1):81-88, (2005).
Abstract:	The role of children's activities in leading to pesticide exposure was evaluated by comparing pesticide loadings on the hands of children with the activities of the same children observed over a 4 hour period. Ten children ranging in age from 24-55 months were videotaped on the second day following a routine professional crack and crevice chlorpyrifos application in their homes. Before and following the video session, the children's hands were rinsed in isopropyl alcohol. Thus, only the chlorpyrifos that accumulated on and remained on the child's hands during the videotaping were removed for analysis after the video taping session. The rinsate was analyzed for chlorpyrifos. The children's behaviors were quantified using Virtual Tracking Device and the frequency and duration of behaviors, the hourly rate of behaviors, and the locations in which behaviors occurred were compared to hand loadings of pesticides. Pesticide hand loadings obtained following the videotaping sessions were associated with pesticide levels on surfaces and toys, but not with air levels. Pesticide loadings obtained following the videotaping sessions were also associated with frequencies, durations, and hourly rates of contact with bottles, and object to mouth behaviors, as well as contact duration with upholstered/textured surfaces. The hand loadings were also associated with the number of locations where the children exhibited object to mouth behavior and with children's use of house space during the videotaping sessions. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under EPA Contract No. 0D-5227-NAEX to the Environmental and Occupational Health Sciences Institute. It has been subjected to Agency review and approved for publication.

JOURNAL	24-Hour Diffusive Sampling of Toxic Vocs in Air Onto Carbopack X Solid Adsorbent Followed By Thermal Desorption/Gc/MS Analysis Laboratory Studies	01/26/2005

MCCLENNY, W. A., K. OLIVER, H. JACUMIN, H. DAUGHTREY, AND D. A. WHITAKER. 24-Hour Diffusive Sampling of Toxic Vocs in Air Onto Carbopack X Solid Adsorbent Followed By Thermal Desorption/Gc/MS Analysis Laboratory Studies. JOURNAL OF ENVIRONMENTAL MONITORING. Royal Society of Chemistry, Cambridge, Uk, 7:248-256, (2005).
Abstract:	Diffusive sampling of a mixture of 42 volatile organic compounds (VOCs) in humidified, purified air onto the solid adsorbent Carbopack X was evaluated under controlled laboratory conditions. The evaluation included variations in sample air temperature, relative humidity, and ozone concentration. Linearity of samples with loading was examined, both for a constant concentration with time varied up to 24 hours, and for different concentrations over 24 hours. Reverse diffusion and its increase with accumulation of sample were determined for all compounds. Tubes were examined for blank levels, for change of blanks with storage time, and for variability of blanks. Method detection levels were determined based on seven replicate samples. After the laboratory evaluation 27 VOCs were selected for quantitative monitoring in the concentration range from approximately 0.1 to 4 ppbv. Comparison of analytical results for active and diffusive samples taken over 24 hours under the same simulated ambient conditions at a constant 2 ppbv were interpreted to estimate the effective diffusive sampling rates (ml min-1) and their uncertainty, and to calculate the corresponding diffusive uptake rates (ng ppmv-1min-1). Many of the rates are reported for the first time. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under contract 68-D-00-206 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication.

JOURNAL	Parameter Evaluation and Model Validation of Ozone Exposure Assessment Using Harvard Southern California Chronic Ozone Exposure Study Data	10/01/2005

XUE, J., S. V. LIU, H. A. OZKAYNAK, AND J. D. SPENGLER. Parameter Evaluation and Model Validation of Ozone Exposure Assessment Using Harvard Southern California Chronic Ozone Exposure Study Data. JOURNAL OF AIR AND WASTE MANAGEMENT ASSOCIATION. Air & Waste Management Association, Pittsburgh, PA, 55:1508-1514, (2005).
Abstract:	To examine factors influencing long-term ozone exposures by children living in urban communities, we analyzed longitudinal data on personal, indoor, and outdoor ozone concentrations as well as related housing and other questionnaire information collected in the one-year-long Harvard Southern California Chronic Ozone Exposure Study. Out of 224 children contained in the original data set, 160 children were found to have longitudinal measurements of ozone concentrations at least in 6 months out of 12 months of study period. Data for these children was randomly split into two equal sets: one for model development and the other for model validation. Mixed models with various variance-covariance structures were developed to evaluate statistically important predictors for chronic personal ozone exposures. Model predictions were then validated against the field measurements using empirical best linear unbiased prediction technique. The results of model fitting showed that the most important predictors for personal ozone exposure include indoor ozone concentration, central ambient ozone concentration, outdoor ozone concentration, season, gender, outdoor time, house fan usage and the presence of a gas range in the house. Hierarchal models of personal ozone concentrations indicate the following levels of explanatory power for each of the predictive models: indoor and outdoor ozone concentrations plus questionnaire variables, central and indoor ozone concentrations plus questionnaire variables, indoor ozone concentrations plus questionnaire variables, central ozone concentrations plus questionnaire variables, and questionnaire data alone on time activity and housing characteristics. These results provide important information on key predictors of chronic human exposures to ambient ozone for children and offer insights into how to reliably and cost-effectively predict personal ozone exposures in the future. Furthermore, the techniques and findings derived from this study also have strong implications for selecting the most reliable and cost-effective exposure study design and modeling approaches for other ambient pollutants, such as fine particulate matter and selected urban air toxics. The United States Environmental Protection Agency through its Office of Research and Development partially funded the research described here. It has been subjected to Agency review and approved for publication.

JOURNAL	Chlorpyrifos Accumulation Patterns for Child Accessible Surfaces and Objectives and Urinary Metabolite Excretion By Children for Two-Weeks After Crack-and-Crevice Application	02/01/2005

HORE, P., M. ROBSON, N. C. FREEMAN, J. ZHANG, D. WARTENBERG, H. A. OZKAYNAK, N. S. TULVE, L. S. SHELDON, L. NEEDHAM, D. BARR, AND P. J. LIOY. Chlorpyrifos Accumulation Patterns for Child Accessible Surfaces and Objectives and Urinary Metabolite Excretion By Children for Two-Weeks After Crack-and-Crevice Application. ENVIRONMENTAL HEALTH PERSPECTIVES. Environmental Health Information Service, 113(2):211-219, (2005).
Abstract:	The Children's-Post-Pesticide-Application-Exposure-Study (CPPAES) was conducted to look at the distribution of chlorpyrifos within a home environment for a 2-week period following a routine professional crack-and-crevice application, and to determine the amount of the chlorpyrifos that is absorbed by a child living within the home. Ten residential homes with a 2-5 year old child in each were selected for study, and the homes were treated with chlorpyrifos. Pesticide measurements were made of the indoor air, indoor surfaces and plush toys. In addition, periodic morning urine samples were collected from each of the children throughout the two-week period. The urine samples were analyzed for 3,5,6-trichloropyridinol, the primary urinary metabolite of chlorpyrifos, and the results were used to estimate the children's absorbed dose. Average chlorpyrifos levels in the indoor air and surfaces ranged from 26 (pre)/120 (post) ng/m³ and 0.48 (pre)/2.8 (post) ng/cm², respectively, reaching peak levels between days 0-2; subsequently, concentrations decreased throughout the 2-week period. Chlorpyrifos in/on the plush toys ranged from 7.3-1949 ng/toy post-application, concentrations increasing throughout the 2-week period demonstrating a cumulative adsorption/absorption process indoors. The daily amount of chlorpyrifos estimated to be absorbed by the CPPAES children post-application ranged from 0.04-4.8 µg/kg/day. During the 2-week period following the crack and crevice application, there was no significant increase in the amount of chlorpyrifos absorbed by the CPPAES children. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under Contract No. 0D-5227-NAEX to the Environmental and Occupational Health Sciences Institute. It has been subjected to Agency review and approved for publication.

JOURNAL	Issues in Dermal Exposure of Infants	07/01/2005

COHEN-HUBAL, E. A. Issues in Dermal Exposure of Infants. JOURNAL OF CHILDREN'S HEALTH. Journal of Children's Health, Weston, MA, 2(3-4):253-265, (2005).
Abstract:	Infants' dermal exposures to environmental contaminants are expected to be different and, in many cases, much higher than adults. Because of the potential importance of the dermal exposure route, there is currently a significant amount of work being conducted to reduce the uncertainties associated with assessing infants' dermal exposures. A conceptual model of dermal exposure is presented and issues associated with characterizing and assessing these exposures presented. Physiological and behavioral characteristics of infants that impact dermal exposure as well as exposure measurement and assessment approaches are discussed.

JOURNAL	Validation of a Method for Estimating Long-Term Exposures Based on Short-Term Measurements	08/01/2005

WALLACE, L. A. AND R. W. WILLIAMS. Validation of a Method for Estimating Long-Term Exposures Based on Short-Term Measurements. RISK ANALYSIS. Blackwell Publishing, Malden, MA, 25(3):687-694, (2005).
Abstract:	A method for estimating long-term exposures from short-term measurements is validated using data from a recent EPA study of exposure to fine particles. The method was developed a decade ago but long-term exposure data to validate it did not exist until recently. In this paper, exposure data from repeated visits to 37 persons over one year (up to 28 measurements per person) are used to test the model. Both fine particle mass and elemental concentrations measured indoors, outdoors, and on the person are examined. To provide the most stringent test of the method, only two single-day distributions are randomly selected for each element to predict the long-term distributions. The precision of the method in estimating the long-term geometric mean and geometric standard deviation appears to be on the order of 10%, with no apparent bias. The precision in estimating the 99th percentile ranges from 19-48%, again without obvious bias. The precision can be improved by selecting a number of pairs of single-day distributions instead of just one pair. Occasionally the method fails to provide an estimate for the long-term distribution. In that case, a repeat of the random selection procedure can provide an estimate. Although the method assumes a log-normal distribution, most of the distributions tested failed the Chi-square test for log-normality. Therefore the method appears suitable for application to distributions that depart from log-normality. The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here under (contract 68-D-99-012) to the RTI International. It has been subjected to Agency review and approved for publication.

JOURNAL	Sampling Artifact Estimates for Alkanes, Hopanes, and Aliphatic Carboxylic Acids	12/01/2005

SIHABUT, T., J. RAY, A. NORTHCROSS, AND S. R. MCDOW. Sampling Artifact Estimates for Alkanes, Hopanes, and Aliphatic Carboxylic Acids. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 39(37):6948-6956, (2005).
Abstract:	Sampling artifacts for molecular markers from organic speciation of particulate matter were investigated by analyzing forty-one samples collected in Philadelphia as a part of the Northeast Oxidant and Particulate Study (NEOPS). Samples were collected using a high volume sampler with two quartz fiber filters in series. n-Alkanes (C23-C31), hopanes (C27-C31), and n-alkanoic acids (C10-C22) were analyzed by gas chromatography-mass spectrometry (GCMS). The extent of artifact error was dependent on vapor pressure and species concentration. Particulate organic species are classified into the following three categories: 1) the amount collected on the backup filter was often a large fraction of the amount collected on the front filters (n-alkanes C23 and C24, n-carboxylic acids C10 to C14); 2) the amount collected on the backup filter was consistently a small fraction of the amount collected on the front filter (n-alkanes C25 to C28, hopanes C27 to C30, n-carboxylic acids C15 to C18, and dicarboxylic acids C3 to C9); 3) the species was rarely observed on backup filters (n-alkanes C29 to C31, hopanes C31 and C32).

JOURNAL	Reaction of Benzene Oxide With Thiols Including Glutathione	01/20/2005

HENDERSON, A. P., M. L. BARNES, C. BLEASDALE, R. CAMERON, W. CLEGG, S. L. HEATH, A. B. LINDSTROM, S. M. RAPPAPORT, S. WAIDYANATHA, W. P. WATSON, AND B. T. GOLDING. Reaction of Benzene Oxide With Thiols Including Glutathione. CHEMICAL RESEARCH IN TOXICOLOGY. American Chemical Society, Washington, DC, 18(2):265-270, (2005).
Abstract:	This study accounts for the observations that the metabolism of benzene is dominated by the formation of phenol. As demonstrated here, the pathway leading to S-phenylmercapturic acid is necessarily minor on account of the low efficiency of benzene oxide capture by glutathione at pH 7 versus spontaneous rearrangement to phenol.

JOURNAL	Use of Personal-Indoor-Outdoor Sulfur Concentrations to Estimate the Infiltration Factor and Outdoor Exposure Factor for Individual Homes and Persons	03/15/2005

WALLACE, L. A. AND R. W. WILLIAMS. Use of Personal-Indoor-Outdoor Sulfur Concentrations to Estimate the Infiltration Factor and Outdoor Exposure Factor for Individual Homes and Persons. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 39(6):1707-1714, (2005).
Abstract:	A study of personal, indoor, and outdoor exposure to PM2.5 and associated elements has been carried out for 37 residents of the Research Triangle Park area in North Carolina. Participants were selected from persons expected to be at elevated risk from exposure to particles, and included 29 persons with hypertension and 8 cardiac patients with implanted defibrillators. Participants were monitored for 7 consecutive days in each of four seasons. One goal of the study was to estimate the contribution of outdoor PM2.5 to indoor concentrations. Using the daily estimated infiltration factor for each house, we calculated the contribution of outdoor PM2.5 to indoor air concentrations. The indoor-generated contributions to indoor PM2.5 had a wider range (0-33 µg/m³) than the outdoor contributions (5-22 µg/m³⁾. However, outdoor contributions exceeded the indoor-generated contributions in 27 of 36 homes. A second goal of the study was to determine the contribution of outdoor particles to personal exposure. The estimates ranged from 0.33 to 0.77 with a median value of 0.53. Outdoor air particles were less important for personal exposures than for indoor concentrations, with the median outdoor contribution to personal exposure just 49%. These values provide an indication of the extent of misclassification error in epidemiological estimates of the effect of outdoor particles on health.

JOURNAL	Preface to Special Section on Particulate Matter Supersites	04/13/2005

PANDIS, S. N., P. A. SOLOMON, AND R. SCHEFFE. Preface to Special Section on Particulate Matter Supersites. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES. American Geophysical Union, Washington, DC, 110:1-3, (2005).
Abstract:	An improved understanding of the key sources, development of the most cost/effective control strategies, and health risks associated with PM2.5 requires high-quality measurements of PM2.5 composition, size and, concentration over a variety of spatial and temporal scales. However, measurement methods for PM2.5, capable of resolving size and composition, had not been thoroughly evaluated when the National Ambient Air Quality Standard for PM2.5 was established, nor previously deployed in regulatory monitoring networks. In response to this need, EPA embarked in 1999 on an ambient monitoring research program, commonly referred to as the Particulate Matter Supersites Program. A Phase I Supersites Program special issue describing results from Atlanta is published (Solomon et al., 2003). The first Phase II Supersites Program special issue is published in Aerosol Science and Technology (Solomon and Allen, 2004) and the second in Atmospheric Environment (Solomon, 2004). This collection of papers, which represents the third coordinated publication of results from the Supersites Program, and addresses the key objectives of the program - to characterize particulate matter, to provide information supporting health effects and exposure research, and to develop new methods for characterizing fine particulate matter. Papers describe results from Supersites Projects in Pittsburgh, PA; Los Angeles, CA; Baltimore, MD; Houston, TX; Atlanta, GA; the North-East Oxidant and Particle Study (NE-OPS); modeling papers using data from Pittsburgh and Atlanta, and a paper examining continuous PM mass methods in Los Angeles, CA and Lindon, UT. Additional coordinated publications of research results are planned to continue to allow the science and policy communities interested in airborne PM to effectively monitor the advances in understanding PM in air made through the Supersites Program.

JOURNAL	Screening for Toxic Industrial Chemicals Using Semipermeable Membrane Devices With Rapid Toxicity Assays	07/06/2005

ROGERS, K. R., S. HARPER, AND G. L. ROBERTSON. Screening for Toxic Industrial Chemicals Using Semipermeable Membrane Devices With Rapid Toxicity Assays. ANALYTICA CHIMICA ACTA. Elsevier Science Ltd, New York, NY, 543(1-2):229-235, (2005).
Abstract:	A time-integrated sampling device interfaced with two toxicity-based assays is reported for monitoring volatile toxic industrial chemicals (TICs). Semipermeable membrane devices (SPMDs) using dimethylsulfoxide (DMSO) as the fill solvent accumulated each of 17 TICs from the vapor phase. Uptake kinetics experiments for one of these compounds (acrolein) indicated that it was significantly concentrated (i.e., 10 percent of the 24 hr maximum) in as little as 10 min and was concentrated by a factor of over 200 for a 24 hr exposure time as measured using both mass and toxicity assays. The effect of each of the TICs on the Microtox bacterial luminescence assay and IQ-Tox Daphnia magna fluorescence assay was determined both from a direct assay and a vapor accumulation assay using SPMDs. Microtox EC₅₀ values (concentrations yielding 50 percent inhibition) were determined for each of the TICs analyzed. The rank order of the Microtox EC₅₀ values for each of the compounds measured by direct dilution of the TICs into assay buffer was similar but not identical to the Apparent (App) EC₅₀ values determined from the vapor accumulation assay. The ratios of the EC₅₀ to the AppEC₅₀ values were used to calculate apparent toxicity-derived concentration factors (i.e., the toxicity equivalents of compound that concentrate from vapor into the SPMD). EC₅₀ values for the IQ-Tox assay as measured using a 90 min fluorescence assay were, in most cases, similar but not identical to the Microtox EC₅₀ values for individual compounds

JOURNAL	META-ANALYSIS OF PHYSICAL ACTIVITY LEVEL ( PAL ) DATA FOR U.S. YOUTH	07/01/2005

MCCURDY, T. R. AND J. XUE. META-ANALYSIS OF PHYSICAL ACTIVITY LEVEL ( PAL ) DATA FOR U.S. YOUTH. JOURNAL OF CHILDREN'S HEALTH. Journal of Children's Health, Weston, MA, 2(3-4):297-319, (2004).
Abstract:	This paper describes analytical research undertaken by EMRB staff to obtain age- and gender-specific distributions of Physical Activity Level (PAL) values for children measured in studies published between 1990-2004 in the clinical nutrition and exercise physiology literatures. These distributions will then be compared to those obtained from NERL's Consolidated Human Activity Database (CHAD) in order to evaluate the representativeness of the data in CHAD. PAL itself is a metric used in the SHEDS and APEX exposure models developed and used by NERL and OAQPS, respectively.

JOURNAL	Airborne Particulate Matter and Human Health: A Review	08/01/2005

DAVIDSON, C. I., R. PHALEN, AND P. A. SOLOMON. Airborne Particulate Matter and Human Health: A Review. AEROSOL SCIENCE AND TECHNOLOGY. Taylor & Francis, Inc., Philadelphia, PA, 39(8):737-749, (2005).
Abstract:	Results of recent research show that PM composition and size vary widely with both space and time. Despite the variability in PM characteristics, which are believed to influence human health risks, the observed relative health risk estimates per unit PM mass falls within a narrow range of values. Furthermore, no single chemical species appears to dominate health effects; rather the effects appear to be due to a combination of species. Non-PM factors such as socioeconomic status and lifestyle are also believed to affect the health risk, although accounting for these confounding factors is challenging. Airborne PM is also responsible for a number of effects aside from human health, such as alterations in visibility and climate. Because the PM problem is associated with a range of societal issues such as energy production and economic development, making progress on reducing the effects of PM will require integrated strategies that bring together scientists and decision makers from different disciplines to consider tradeoffs holistically.

JOURNAL	Electrochemically Deposited Polymer-Coated Gold Electrodes Selective for 2,4-Dichlorophenoxyacetic Acid	10/01/2005

WEETALL, H., D. W. HATCHETT, AND K. R. ROGERS. Electrochemically Deposited Polymer-Coated Gold Electrodes Selective for 2,4-Dichlorophenoxyacetic Acid. ELECTROANALYSIS. Wiley-VCH, Weinheim, Germany, 17(19):1789-1794, (2005).
Abstract:	Electropolymerized membranes on gold electrodes doped with 2,4-dichlorophenoxyacetic acid (2,4-D) were prepared from a solution containing resorcinol, o-phenylenediamine and 2,4-D. Fourier Transform Infrared (FTIR) spectroscopy was used to evaluate the incorporation and interaction of 2,4-D with the polymer matrix prior to and after the sensing experiments. The FTIR data indicate that 2,4-D does not leach appreciably from the polymer matrix under experimental conditions employed for the sensing studies. The electrochemical current response for 2,4-D is compared for the doped polymer-coated and control polymer-coated electrode. The response of the doped polymer-electrode was dependent on increasing concentrations of 2,4-D and 2,4-dichlorophenol while unresponsive to benzoic acid.

JOURNAL	Summertime Ambient Formaldehyde in Five U.S. Metropolitan Areas: Nashville, Atlanta, Houston, Philadelphia, Tampa	07/01/2005

DASGUPTA, P. K., J. LI, G. ZHANG, W. T. LUKE, W. A. MCCLENNY, J. STUTZ, AND A. FREID. Summertime Ambient Formaldehyde in Five U.S. Metropolitan Areas: Nashville, Atlanta, Houston, Philadelphia, Tampa. ENVIRONMENTAL SCIENCE AND TECHNOLOGY. John Wiley & Sons, Ltd., Indianapolis, IN, 39(13):4767-4783, (2005).
Abstract:	In this paper, we briefly review the atmospheric chemistry and previous intercomparison measurements for HCHO, with special reference to the diffusion scrubber-Hantzsch reaction based fluorescence instrument used in the field studies reported herein. Then we discuss summertime HCHO levels in 5 major US cities measured over 1999-2002, primarily from ground-based measurements. Land-sea breeze circulations play a major role in observed concentrations in coastal cities. Very high HCHO peak mixing ratios were observed in Houston (>47 ppb) where the overall median mixing ratio was 3.3 ppb, the corresponding values in Atlanta were ~>18 and 7.9 ppb, respectively. The peak and median mixing ratios (9.3 and 2.3 ppb) were the lowest for Tampa, where the land-sea breeze also played an important role. In several cities, replicate HCHO measurements were made by direct spectroscopic instruments; the instruments were located kilometers from each other and addressed very different heights (e.g.,106 m vs. 10 m). Even under these conditions, there was remarkable qualitative and often quantitative agreement between the different instruments, when they were all sampling the same airmass within a short period of each other. Local chemistry dominates how HCHO is formed and dissipated. The high concentrations in Houston unequivocally resulted from emissions near the ship channel; the same formaldehyde plume was measured at two sites and clearly ranged over tens of km. Local micrometeorology is another factor. HCHO patterns measured at a high rise site in downtown Nashville were very much in synchrony with other ground sites 12 km away until July 4 celebrations whence nighttime HCHO concentrations at the downtown site remained elevated for several days. The formation and dissipation of HCHO in the different cities are discussed in terms of other concurrently measured species and meteorological vectors. The vertical profiles of HCHO in and around Tampa under several different atmospheric conditions are presented. The extensive data set represented in this paper underscores that urban formaldehyde measurements can now be made easily; the agreement between disparate instruments (that are independently calibrated or rely on the absolute absorption cross section) further indicates that such measurements can be done reliably and accurately for this very important atmospheric species. The data set presented here can be used as a benchmark for future measurements if the use of formaldehyde precursors such as methanol or methyl tert-butyl ether (MTBE) as oxygenated fuel additives increase in the future.

JOURNAL	Sampling Artifacts in Measurement of Elemental and Organic Carbon: Low Volume Sampling in Indoor and Outdoor Environments	09/01/2005

OLSON, D. A. AND G. A. NORRIS. Sampling Artifacts in Measurement of Elemental and Organic Carbon: Low Volume Sampling in Indoor and Outdoor Environments. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 39(30):5437-5445, (2005).
Abstract:	Experiments were completed to determine the extent of artifacts from sampling elemental carbon (EC) and organic carbon (OC) under sample conditions consistent with personal sampling. Two different types of experiments were completed; the first examined possible artifacts from oils used in personal environmental monitor (PEM) impactor plates, and the second examined artifacts from microenvironmental sampling using different sampling media combinations (quartz, Teflon, XAD denuder, and electrostatic precipitator). Three microenvironments were tested (kitchen, library, and ambient); carbon concentrations were highest in the kitchen using a front quartz filter (mean OC of 16.4 µg/m^-3). The lowest front quartz filter concentrations were measured in the library using XAD denuders (mean OC of 3.6µg m^-3). Denuder removal efficiencies (average of 82% for total carbon) were lower compared with pervious ambient studies and may indicate that indoor sources influenced denuder efficiency during sample collection. The highest carbon concentrations from backup quartz filters were measured using the Teflon-quartz combination.

JOURNAL	Development and Evaluation of An Enzyme-Linked Immunoassay (ELISA) Method for the Measurement of 2,4-Dichlorophenoxyacetic Acid in Human Urine	09/15/2005

CHUANG, J. C., J. M. VAN EMON, J. DURNFORD, AND K. W. THOMAS. Development and Evaluation of An Enzyme-Linked Immunoassay (ELISA) Method for the Measurement of 2,4-Dichlorophenoxyacetic Acid in Human Urine. TALANTA. Elsevier Science Ltd, New York, NY, 67(3):658-666, (2005).
Abstract:	This paper describes the development of a 96-microwell high sample capacity ELISA method for measuring 2,4-D in urine; the analysis of 2,4-D in real-world urine samples by both ELISA and GC/MS methods; and compares the ELISA and GC/MS results in several key areas: accuracy, precision, sample throughput and detection limits.

JOURNAL	Formation of 2-Methyl Tetrols and 2-Methylglyceric Acid in Secondary Organic Aerosol from Laboratory Irradiated Isoprene/No _x/So ₂/Air Mixtures and Their Detection in Ambient PM _2.5 Samples Collected in the Eastern United States	10/01/2005

EDNEY, E. O., T. E. KLEINDIENST, M. JAOUI, M. LEWANDOWSKI, J. H. OFFENBERG, W. WANG, AND M. CLAEYS. Formation of 2-Methyl Tetrols and 2-Methylglyceric Acid in Secondary Organic Aerosol from Laboratory Irradiated Isoprene/No _x/So ₂/Air Mixtures and Their Detection in Ambient PM _2.5 Samples Collected in the Eastern United States. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 39(32):5281-5289, (2005).
Abstract:	A series of isoprene/NOx/air irradiation experiments, carried out in both the absence and presence of SO2, were conducted to assess whether isoprene contributes to secondary organic aerosol (SOA) formation. In the absence of SO2 , the SOA yield of 0.002 was low. However, in the presence of SO2, the SOA yield increased significantly to 0.028 and 2-methylthreitol, 2-methylerythritol and 2-methylglyceric acid were detected in the laboratory SOA samples. These same compounds have been observed in ambient PM2.5 samples collected in the eastern United States. These results suggest isoprene may be contributing to ambient PM2.5, although additional research is required to accurately determine its contribution.

JOURNAL	Identification and Quantification of Aerosol Polar Oxygenated Compounds Bearing Carboxylic or Hydroxyl Groups. 2. Organic Tracer Compounds from Monoterpenes	08/01/2005

JAOUI, M., T. E. KLEINDIENST, M. LEWANDOWSKI, J. H. OFFENBERG, AND E. O. EDNEY. Identification and Quantification of Aerosol Polar Oxygenated Compounds Bearing Carboxylic or Hydroxyl Groups. 2. Organic Tracer Compounds from Monoterpenes. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 39(15):5661-5673, (2005).
Abstract:	A comparison was made of polar organic compounds found in the field with those produced in secondary organic aerosol from laboratory irradiations of natural hydrocarbons and oxides of nitrogen. The field samples comprised atmospheric particulate matter (PM_2.5) collected at RTP, NC during the summer 2003, and the laboratory samples originated from the photooxidation of the following monoterpenes: 1-pinene, 2-pinene, and d-limonene. Seven multifunctional organic compounds were found in both field and laboratory samples. The occurrence of these compounds in both laboratory and field measurements suggests that secondary organic aerosol originating from monoterpenes are contributing to the regional aerosol burden in the southeastern United States.

JOURNAL	Dicarboxylic Acid Concentration Trends and Sampling Artifacts	12/01/2005

RAY, J. AND S. R. MCDOW. Dicarboxylic Acid Concentration Trends and Sampling Artifacts. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 39(40):7906-7919, (2005).
Abstract:	Dicarboxylic acids associated with airborne particulate matter were measured during a summer period in Philadelphia that included multiple air pollution episodes. Samples were collected for two ten hour periods each day using a high volume sampler with two quartz fiber filters in series and analyzed by gas chromatography-mass spectrometry (GCMS) with diazomethane derivatization. Among the dicarboxylic acids investigated, phthalic acid and adipic acid exhibited the greatest diurnal variations and the strongest linear relationship with maximum daily ozone concentration. Dicarboxylic acids and ozone concentration exhibited a poor linear relationship with organic to elemental carbon ratio. All species investigated were affected by significant sampling artifact errors at low concentrations, but sampling errors were negligible at high concentrations observed during ozone episodes.

JOURNAL	Atmospheric Mercury Behavior at Different Altitudes at Ny-Alesund During Spring 2003	12/01/2005

SPROVIERI, F., N. PIRRONE, M. S. LANDIS, AND R. K. STEVENS. Atmospheric Mercury Behavior at Different Altitudes at Ny-Alesund During Spring 2003. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 39(39):7646-7656, (2005).
Abstract:	Intensive field measurements of atmospheric mercury and related species were carried out in Ny Alesund, Spitsbergen during the spring of 2003 at two altitudes. Measurements were made at the Italian research station Dirigibile Italia (12m a.s.l.) and on the top of Zeppelin Mountain at the Norwegian Research Station (474m a.s.l.). Ambient concentrations of gaseous elemental mercury, divalent reactive gaseous mercury and particulate phase mercury were semi-continuously measured at both sites using an integrated Tekran system. Atmospheric elemental gaseous mercury depletion events (AMDEs) were observed at both locations, the lowest observed Hg⁰ concentration was 0.3 ng m^-3. At sea level, mercury species concentrations following AMDEs were found to be higher and to exhibit larger variability in comparison to results observed at Zeppelin station.

JOURNAL	Emissions of Metals Associated With Motor Vehicle Roadways	02/01/2005

LOUGH, G. C., J. J. SCHAUER, J. PARK, M. M. SHAFER, J. T. DEMINTER, AND J. P. WEINSTEIN. Emissions of Metals Associated With Motor Vehicle Roadways. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 39(3):826-836, (2005).
Abstract:	Emissions of metals and other particle-phase species from on-road motor vehicles were measured in two tunnels in Milwaukee, WI during the summer of 2000 and winter of 2001. Emission factors were calculated from measurements of fine (PM_2.5) and coarse (PM₁₀) particulate matter at tunnel entrances and exits, and effects of fleet composition and season were investigated. Cascade impactors (MOUDI) were used to obtain size-resolved metal emission rates. Metals were quantified with inductively-coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence (XRF). PM₁₀ emission rates ranged from 38.7 to 201 mg km-1 and were composed mainly of organic carbon (OC, 30%), inorganic ions (sulfate, chloride, nitrate, ammonium, 20%), metals (19%), and elemental carbon (EC, 9.3%). PM₁₀ metal emissions were dominated by crustal elements Si, Fe, Ca, Na, Mg, Al, and K, and elements associated with tailpipe emissions and brake and tire wear, including Cu, Zn, Sb, Ba, Pb, and S. Metals emitted in PM_2.5 were lower (11.6% of mass). Resuspension of roadway dust was dependent on weather and road surface conditions, and increased emissions were related to higher traffic volumes and fractions of heavy trucks. Emission of noble metals from catalytic converters appeared to be impacted by the presence of older vehicles. Elements related to brake wear were impacted by enriched road dust resuspension, but correlations between these elements in PM_2.5 indicate that direct brake wear emissions are also important. A submicrometer particle mode was observed in the emissions of Pb, Ca, Fe, and Cu.

PAPER IN NON-EPA PROCEEDINGS	Quantitation, Detection and Measurement Precision of Organic Molecular Markers in Urban Particulate Matter from Philadelphia, Pa	06/21/2005

LI, M., S. R. MCDOW, D. J. TOLLERUD, AND M. A. MAZUREK. Quantitation, Detection and Measurement Precision of Organic Molecular Markers in Urban Particulate Matter from Philadelphia, Pa. In Proceedings, Air & Waste Management Association 98th Annual Conference and Exhibition, Minneapolis, MN, June 21 - 24, 2005. Air & Waste Management Association, Pittsburgh, PA, 1-20, (2005).
Abstract:	This work focuses on analysis of organic molecular markers in airborne particulate matter (PM) by Gas Chromatography/Ion Trap Mass Spectrometry (GC/IT MS). The particulate samples used in the method development were collected as PM₁₀ in metropolitan Philadelphia during 2000.

PRESENTATION	(Present at Nccu) Analysis of Selected Pyrethroid Pesticides Using Reverse Phase High Liquid Chromatography	03/18/2005

MORRISON, C., J. M. STARR, AND E. M. ULRICH. (Present at Nccu) Analysis of Selected Pyrethroid Pesticides Using Reverse Phase High Liquid Chromatography. Presented at NC Louis Stokes Alliance for Minority Participation Program, Durham, NC, March 18, 2005.
Abstract:	This research was conducted in cooperation with EPA Region 4 in Athens, GA to develop a method to analyze selected pyrethroid pesticides using Reverse Phase-High Pressure Liquid Chromatography (HPLC). This HPLC method will aid researchers in separating and identifying these pyrethroids. The method was developed for Type I pyrethroids without a cyano group (allethrin, permethrin, resmethrin) and Type II pyrethroids with a cyano group (cypermethrin and fenvalerate). The pyrethroids were separated on a Hewlett Packard model 1090 using a Phenomenex C-18 100 2.0 mm SYNERGI 4u Hydro-RP 80A column. The flow rate was set at 0.5 mL/min. at 350C using two mobile phases consisting of acetonitrile-distilled water (1:1, v/v) and methanol-acetonitrile-distilled water (0.5:0.5:1, v/v) with 10 5L injections. The ratios of aqueous to organic mobile phase evaluated ranged from 10:90 to 60:40. Mobile phase conditions of 20% water and 80% acetonitrile separated allethrin (2.207 minutes), resmethrin isomers (7.997, 8.414 minutes), and permethrin isomers (9.631, 11.326 minutes), respectively. Analysis of the pyrethroids separately allows us to hypothesize that, in an unknown sample, complete separation occurs. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names of commercial products does not constitute endorsement or recommendation for use.

PRESENTATION	(Presented Naqc San Francisco, Ca) Coarse PM Methods Study: Study Design and Results	02/08/2005

VANDERPOOL, R., T. G. ELLESTAD, P. A. SOLOMON, S. NATARAJAN, C. NOBLE, R. MURDOCH, J. AMBS, J. TISCH, AND G. SEM. (Presented Naqc San Francisco, Ca) Coarse PM Methods Study: Study Design and Results. Presented at 2005 National Air Quality Conference, San Francisco, CA, February 12 - 16, 2005.
Abstract:	Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discrete difference method was used which employs two designated FRM samplers, one to measure PM2.5 and the other PM10. The numerical difference of these reference method concentrations (PM10-PM2.5) represented an estimate of PMc. A second sampling approach involved a sequential dichotomous sampler, which provided both PM2.5 and PMc measurements. In both of these filter-based, time-integrated measurement approaches, the collected aerosol mass was analyzed gravimetrically in the laboratory under controlled conditions. Three continuous coarse particle samplers that measure PMc directly with a time resolution of 1 hour or less were also evaluated. One such sampler was a commercially available system based on beta attenuation, the second was based on TEOM technology. Both of these measurement approaches used dichotomous virtual impactors for separating fine and coarse particles. The third real-time sampler evaluated was an aerodynamic particle sizer (APS) that measures the aerodynamic diameter of individual particles, calculates the mass of the particle based on an assumed particle density, then sums the mass within the size range of interest to estimate the PMc mass concentration. Sampling sites and timing of the studies were selected to provide diverse challenges to the samplers with respect to aerosol concentration, aerosol particle size distribution, and aerosol composition. Results from performance evaluations of the candidate PMc samplers at Gary, IN, Phoenix, AZ, and Riverside, CA will be presented. This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION	(Presented at Matsuyama, Japan) Persistent Perfluorinated Organic Compounds Method Development Research at the U.S. Environmental Protection Agency	01/10/2005

LINDSTROM, A. B. AND M. J. STRYNAR. (Presented at Matsuyama, Japan) Persistent Perfluorinated Organic Compounds Method Development Research at the U.S. Environmental Protection Agency. Presented at Center for Marine Environmental Studies, Ehime University, Matsuyama, JAPAN, January 10, 2005.
Abstract:	PowerPoint presentation summarizing method development research involving the persistent perfluorinated organic compounds. Review of data indicating widespread distribution of these materials and the potential for toxicity.

PRESENTATION	The Detroit Exposure and Aerosol Research Study (Dears): Briefing to the Michigan Department of Environmental Quality	01/31/2005

WILLIAMS, R. W., A. F. VETTE, C. W. CROGHAN, AND C. D. STEVENS. The Detroit Exposure and Aerosol Research Study (Dears): Briefing to the Michigan Department of Environmental Quality. Presented at Michigan Department of Environmental Quality, Detroit, MI, January 31, 2005.
Abstract:	The Detroit Exposure and Aerosol Research Study (DEARS) has completed its first monitoring season (summer 2005) and is progressing toward initiation of its second season (February 2005). The assistance obtained from the Michigan Department of Environmental Quality has been instrumental in this success as well as those of other collaborating institutions. This briefing will provide an overview of the study's goal and purposes, the research accomplishments to date and an understanding of current efforts to support the winter 2005 field monitoring effort. A preliminary report on summer 2004 monitoring efforts will be provided. These data indicate that: (1) the study was successful in the recruitment and retention of Wayne County residents during the 1st season, (2) the success of the study has been the result of continued cooperation between numerous governmental, academic, and private organizations, (3) an analysis of summer 2004 data indicates that the methodologies utilized in the monitoring would appear to be successful in detecting environmental analytes of interest, (4) fine particulate matter concentrations appear to have been homogeneous across the study area as indicative by mean concentrations normalized to those collected at Allen Park , and (5) a number of new collaboration efforts will be initiated during the winter 2005 monitoring season such as the Healthy Heart Study). Although this work was reviewed by the EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Molecular Composition of Organics in PM 2.5 at the New York City Supersite Winter 2004	02/09/2005

LI, M., M. MAZUREK, S. R. MCDOW, J. SCHWAB, K. DEMERJIAN, AND D. FELTON. Molecular Composition of Organics in PM 2.5 at the New York City Supersite Winter 2004. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	Organic compounds in PM2.5 were studied at the New York City Supersite at Queens College, NYC as part of the NYC Supersite Winter 2004 Intensive from January 15 to February 5, 2004. The Queens fine particle samples were collected on a daily basis. Eight composites containing 3 to 4 filters were generated to provide sufficient organic carbon (OC) mass for the determination of individual organic molecular tracers within the OC fraction. A field blank composite (extracted exactly as the ambient PM2.5 filters) and a trip blank composite were analyzed to monitor sampling and analytical background levels of the OC molecular constituents. The filter composites were extracted with organic solvent (1:1 methylene chloride:acetone) and analyzed for 52 molecular marker compounds by gas chromatography/ion trap mass spectrometry (GC/IT MS). Normal alkanes (C25 to C32), n-alkanoic acids (C10 to C30), dicarboxylic acids (C3 to C9) and hopanes (C27 to C32) were identified in most sample composites. Ambient mass concentrations for these molecular marker groups were determined. Ratios of the ambient mass concentrations of the molecular markers to the EC and the OC fractions were established to study wintertime variation of urban emission sources in the metropolitan New York City area. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Reference Materials and Quality Assurance for the Characterization of Organic Compounds in Particulate Matter	02/09/2005

SCHANTZ, M., S. WISE, S. R. MCDOW, AND J. JUNGERS. Reference Materials and Quality Assurance for the Characterization of Organic Compounds in Particulate Matter. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	One of the first environmental matrix Standard Reference Materials (SRMs) developed by the National Institute of Standards and Technology (NIST) for determination of organic species was SRM 1649 Urban Dust, ambient total suspended particulate matter (PM) collected in Washington DC in the late 1970's. Since SRM 1649 was issued in 1981, it has found widespread use in the PM measurement community, and NIST has assigned values for over 100 organic species in this material. However, there is a growing need for additional SRMs to support organic speciation in PM, particularly for the fine PM fraction and representative of contemporary combustion sources. NIST is collaborating with the U.S. Environmental Protection Agency (EPA) to develop SRMs and to provide interlaboratory comparison exercises to improve the accuracy and comparability of organic speciation measurements in PM. As part of the NIST/EPA collaboration, the Organic Speciation Working Group was formed in 2000 to assist in this effort by participating in interlaboratory comparison studies and to provide input for the development of SRMs to support these measurements. This group has participated in three interlaboratory comparison studies for the determination of polycyclic aromatic hydrocarbons (PAHs), nitrated PAHs, alkanes (including hopanes and cholestanes), sterols, carbonyl compounds (ketones and aldehydes), acids (alkanoic and resin), phenols, and sugars in PM-related samples. Because these interlaboratory comparison studies are performance-based, participating laboratories are encouraged to use the analytical methods that they routinely use in their laboratories to analyze PM samples. The results from the participating laboratories, following outlier testing, are used to assign a consensus concentration for each analyte in the unknown PM samples. Results are used in the consensus value assignment for the unknown PM sample only if the laboratory's results for analysis of SRM 1649a Urban Dust, which is provided as a control material, are within 30% of the uncertainty limits of the certified values. The consensus values, accuracy and precision assessments, and the methods used by each laboratory are summarized in a report provided to the participants. The third NIST/EPA interlaboratory study was recently completed, and the results will be presented. Based on the results of these studies, the list of target analytes has been refined and priorities for the development of SRMs have been identified. Calibration solution SRMs are currently under development for: polycyclic aromatic hydrocarbons (PAHs) (two redesigned solutions with an expanded list of 53 PAHs and alkyl-substituted PAHs), aliphatic hydrocarbons, nitro-substituted PAHs (redesigned with an expanded list of 27 compounds), hopanes/steranes, and 13C-labeled and deuterium-labeled levoglucosan (for use as internal standards). The status of the development of these organic solution SRMs and the priorities for future SRM development will be discussed. This work has been funded in part by the U.S. Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION	Estimating Uncertainities in Factor Analytic Models	02/09/2005

EBERLY, S. I., P. PAATERO, AND P. K. HOPKE. Estimating Uncertainities in Factor Analytic Models. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	When interpreting results from factor analytic models as used in receptor modeling, it is important to quantify the uncertainties in those results. For example, if the presence of a species on one of the factors is necessary to interpret the factor as originating from a certain emission source category or source region, then that species should be present on that factor with high certainty. In this work, we examine three methods for determining uncertainties of computed factors, F, and their respective time series, G, in the non-negatively constrained factor analytic model X=G*F+E, as applied in atmospheric sciences. The methods include linear error propagation of uncertainties of X separately to G and separately to F, bootstrapping, and bootstrapping enhanced with random rotational forcing to provoke rotations in G and F. Linear error propagation is simple to describe and implement. However, since the errors in X are not always well known in environmental applications and since the factor analytic model is non-linear by definition, the uncertainty estimates from linear error propagation are questionable. Bootstrapping is also simple to describe although computer intensive when implemented, but it, similar to linear error propagation, assumes that the solution is unique and therefore ignores the uncertainty that arises from the rotational ambiguity in the results. The methods are applied to simulated data where X, F, and G, and the uncertainties in X are known. By using simulated data, we can compare the F and G uncertainties, as estimated by the three methods, with the differences (estimated value minus true value) of F and G. When tested on simulated data with low errors and without rotational freedom, all three methods agree favorably. When the error levels are increased, the bootstrap methods produce better uncertainty estimates than linear error propagation. Finally, when rotational freedom is introduced to the simulated data, bootstrapping with rotational forcing reproduces the uncertainties in computed F and G most accurately. Next the methods are applied to a real atmospheric data set where unknown errors are present. Real aerosol data from Phoenix (1995-1998) are analyzed. Computed error limits are compared with source profiles that have been used in previous source apportionment studies for Phoenix. Bootstrapping with rotational forcing is applied with parameters as optimized based on the simulated data. The computed confidence intervals mostly cover the true values, although a confidence percentage cannot be quoted. Lastly, we show how the uncertainty estimates are impacted by the assumed errors in X. For some species, even if the assumed errors are doubled, the uncertainty estimates from bootstrapping remain the same. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Field Evaluation of a High-Volume Dichotomous Sampler	02/09/2005

SARDAR, S. B., B. CHAKRABARTI, M. D. GELLER, C. SIOUTAS, AND P. A. SOLOMON. Field Evaluation of a High-Volume Dichotomous Sampler. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	This study presents the field evaluation of a high-volume dichotomous sampler that collects coarse (PM10-2.5) and fine (PM2.5) particulate matter. The key feature of this device is the utilization of a round-nozzle virtual impactor with a 50% cutpoint at 2.5 5m to split PM10 into its coarse and fine fractions at a very high flow rate. The high-volume dichotomous sampler operates at a total flow rate of 1100 lpm with major and minor flows of 1000 and 100 lpm, respectively. The virtual impactor was characterized in the Particle Instrumentation Unit of the Southern California Particle Center and Supersite (SCPCS), with ambient aerosols before it was put into its current configuration. Furthermore, to evaluate its performance, the virtual impactor was connected to a 100 lpm virtual impactor (2.5 5m cut point) in series, and ambient aerosols were measured using an aerodynamic particle sizer (APS, Model 3320, TSI Inc). By connecting the two virtual impactors in series, concentration enrichment of 150 times ambient was achieved. The high-volume dichotomous sampler was then collocated with a MOUDI (Micro Orifice Uniform Deposit Impactor, Model 110, MSP Corporation, Minneapolis, MN) and a dichotomous PM10 Partisol sampler (Model 2025, R & P) at the University of Southern California in Los Angeles. The MOUDI and the high-volume sampler agreed well, with an average ratio (N = 19) of high-volume to MOUDI measured coarse PM concentration being 0.84 1 0.08. Similarly, good agreement was also observed between the high-volume dichotomous sampler and the Partisol (Ratio of the high-volume to Partisol is found to be 0.86 1 0.1). In addition to time-integrated coarse PM mass measurements, filter and impaction substrate samples were analyzed for inorganic ions (nitrate and sulfate), elemental carbon (EC) and organic carbon (OC) and will also be compared as part of further investigation in this study. The ultimate goal of this study was to demonstrate the feasibility of using this high-volume dichotomous sampler as an effective system to collect simultaneously sufficient coarse and fine mass samples for improving the sensitivity for organic aerosol speciation and the measurement of potentially toxic compounds and to allow for comprehensive standard chemical analysis over short time intervals as may be desired from one filter set for source apportionment studies or other data analysis and modeling efforts. Subsequent analysis of the filters may then lend itself to quick speciation/identification of ambient PM. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Comparison of Data from the Stn and Improve Networks	02/09/2005

MCDADE, C. E., W. H. WHITE, N. P. HYSLOP, P. A. SOLOMON, T. KLAMSER-WILLIAMS, D. CRUMPLER, AND P. P. EGEGHY. Comparison of Data from the Stn and Improve Networks. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	Two national chemical speciation-monitoring networks operate currently within the United States. The Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network operates primarily in rural areas collecting aerosol and optical data to better understand the causes of regional haze in Class I areas. IMPROVE began operation in 1988. The Speciation Trends Network (STN) operates in urban locations collecting aerosol data to better understand the causes of PM2.5 levels that exceed the National Ambient Air Quality Standards for Particulate Matter (PM) established in 1997. STN began operation in late 2000. EPA desires to integrate data from both networks to allow for a regional approach to reducing PM in urban areas since concentrations of PM in urban areas are strongly influenced by regional levels. While both networks are based on 24-hour filter sampling, there are differences in the sampling and chemical analysis methods employed. These differences range from the inlet of the samplers to how data are processed before final concentrations are reported. EPA, in conjunction with UC Davis and others, has conducted collocated sampling since October 2001 at three sets of paired urban-rural sites (Washington, DC; Phoenix, AZ; and Seattle, WA). Collocated STN and IMPROVE samplers were operated at all sites and analyzed for major components (sulfate, nitrate, organic carbon, and elemental carbon) and trace elements (e.g., Fe, Ca, Si). Each network followed its own specific protocols. Comparison results from the first year of sampling (October 2001-September 2002) have been reported previously. This paper expands those analyses by incorporating the second year (October 2002-September 2003). Furthermore, IMPROVE initiated its own in-network collocated sampling program during 2003 to assess the precision of IMPROVE data. Those precision data are utilized to provide a baseline for comparing aerosol data from the two different networks. The approach for doing so is described in a companion paper at this conference (White, et al., 2005). Reference: Warren H. White, Nicole P. Hyslop, and Charles E. McDade, "Using In-Network Precision Data as a Basis for Cross-Network Comparisons" (2005). Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	High Volume Injection for Gcms Analysis of Particulate Organic Species in Ambient Air	02/09/2005

TURLINGTON, J., D. A. OLSON, J. VOLCKENS, L. STOCKBURGER, AND S. R. MCDOW. High Volume Injection for Gcms Analysis of Particulate Organic Species in Ambient Air. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	Detection of organic species in ambient particulate matter typically requires large air sample volumes, frequently achieved by grouping samples into monthly composites. Decreasing the volume of air sample required would allow shorter collection times and more convenient sample collection, potentially resulting in more distinctive source mixtures and expansion of source apportionment capabilities to micro-environmental applications. Most previous efforts for GCMS analysis of airborne particulate matter used splitless injection, which limits sensitivity by permitting injection of only a small fraction of the total extract. The Human Exposure and Atmospheric Sciences Division recently developed Organic Aerosol Laboratory has completed characterization of a high volume injection method with increases analytical sensitivity by allowing injection of a considerably larger fraction of the extract. Samples are extracted under pressure using a Dionex Accelerated Solvent Extractor in 1:1:1 pentane:dichloromethane:acetone for measurement of both polar and non-polar compounds. Extracts are concentrated and introduced into an Agilent 6890 GC with a 5973 MS Detector by injection of 100 microliters with a Gerstel Programmable Temperature Vaporization Injector. Reproducibility of five point calibration curves run in triplicate have been demonstrated for eleven n-alkanes, three hopanes, and seven polycyclic aromatic hydrocarbons. Linear correlation coefficients for individual calibration curves for hopanes and polycyclic aromatic hydrocarbons in all cases were r² > 0.999 and for n-alkanes in all cases were r² > 0.998. Relative standard deviations in response factors without exception were under 3% for concentrations greater than 150 picograms per microliter under 20% for concentrations between 5 and 150 picograms per microliter. Although high signal-to-noise ratios were observed at concentrations as low as 1.5 picograms per microliter, precision between calibration curves was poor. These results indicate a capability of determining concentrations with good precision for all compounds at concentrations as low as 50 picograms per cubic meter even for a 24-hour 10 liter per minute sample. Although this work was reviewed by EPA and approved for publication, it may not reflect official Agency policy.

PRESENTATION	Semi-Volatile Secondary Aerosols in Urban Atmospheres: Meeting a Measured Challenge	02/08/2005

WILSON, W. E., B. D. GROVER, N. L. EATOUGH, D. J. EATOUGH, AND R. W. LONG. Semi-Volatile Secondary Aerosols in Urban Atmospheres: Meeting a Measured Challenge. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	This presentation compares the results from various particle measurement methods as they relate to semi-volatile secondary aerosols in urban atmospheres. The methods include the PM2.5 Federal Reference Method; Particle Concentrator - BYU Organic Sampling System (PC-BOSS); the Real-time Ambient Mass Sampler (RAMS); the FDMS TEOM, and the GRIMM monitor. Total concentrations of PM2.5 including semi-volatile species can be measured with the PC-BOSS, RAMS and FDMS. The GRIMM monitor also measures SVM but appears to respond to particle bound water. The FRM can overestimate or underestimate PM2.5 mass depending on meteorological conditions. The TEOM monitor does not accurately determine total particulate matter due to loss of semi-volatile mass. Although this work was reviewed by EPA and approved for presentation, it may not necessarily reflect official Agency policy

PRESENTATION	Influence of Regional Particulate Matter on Selected Urban Areas Across the U.S.	02/10/2005

KLAMSER-WILLIAMS, T., P. A. SOLOMON, P. P. EGEGHY, D. CRUMPLER, J. RICE, J. B. HOMOLYA, AND C. MCDADE. Influence of Regional Particulate Matter on Selected Urban Areas Across the U.S. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	Over the next few years, states will be required to develop state implementation plans for reducing concentrations of fine particles in air where, PM2.5 annual and or daily standards are exceeded. It is now well recognized that high concentrations of PM2.5 in urban areas are in part due to transport of fine particles and particle precursors from upwind locations and that problem is in fact regional, especially in the eastern U.S.. To better understand the sources of PM2.5, the U.S.. EPA has established a national chemical Speciation Trends Network (STN) in urban areas, which provides information on the major and some minor chemical components of PM2.5. This network was initiated in 1999. EPA also has enhanced significantly the number of rural IMPROVE Speciation Monitoring Sites nationally and, combined, these networks provide a fairly comprehensive picture of PM mass and its chemical composition throughout the U.S. To better understand potential differences between the two networks, EPA is evaluating data from an initial comparison of 3 urban-rural sites where collocated samplers from both networks operate based on each network's specific protocols for sampling and analysis. These sites are located in the areas of Washington, D.C., Phoenix, AZ, and Seattle, WA. The sites were chosen to expose the samplers to different ambient chemical and meteorological conditions. This presentation describes the chemical characteristics observed between the urban-rural pairs and the variation of those pairs in different parts of the country during the first year of the study. The regional component, estimated by the rural site, dictates the fraction of the local component that needs to be lowered due to local emissions controls on primary PM and PM precursors and allows for a suggestion of how regional controls may benefit areas out of compliance with current PM standards. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Use of the Aerodynamic Particle Sizer to Measure PM-Coarse	02/10/2005

PETERS, T., R. VANDERPOOL, AND S. NATARAJAN. Use of the Aerodynamic Particle Sizer to Measure PM-Coarse. Presented at American Association of Aerosol Research 2005, Atlanta, GA, February 07 - 11, 2005.
Abstract:	The aerodynamic particle sizer (APS 3321, TSI, Inc.) measures particle size distributions from 0.5 µm to 20 µm by determining the time-of-flight of individual particles in an accelerating flow field. A complete particle size distribution may be determined in a matter of seconds, making the APS ideal for assessing rapid fluctuations in atmospheric PM-coarse. Recent laboratory tests show that the APS 3321 can sample PM-coarse-sized particles with near 100% efficiency if they are solid; however, this efficiency becomes substantially lower for liquid droplets. This work compared PM-coarse measurements made with 24-hr, filter-based PM samplers to that measured with the APS. Two APS 3321 instruments with PM-10 and PM-2.5 samplers were deployed in four field campaigns in three U.S. cities: Gary, IN, Riverside, CA, and Phoenix, AZ. To collect representative aerosol samples, each APS sampled isokinetically from the downtubes of a standard 16.7-Lpm, FRM PM-10 inlet. In addition to comparing 24-hr measurements, the APS data were investigated to observe trends in temporal and size variability of the PM-coarse aerosol. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names of commercial products does not constitute endorsement or recommendation for use.

PRESENTATION	Radiocarbon ¹⁴c Measurements on Atmospheric Samples of Particulate Matter (& Volatile Organic Compounds)	02/17/2005

LEWIS, C. W. Radiocarbon ¹⁴c Measurements on Atmospheric Samples of Particulate Matter (& Volatile Organic Compounds). Presented at Lawrence Livermore National Laboratory, Livermore, CA, February 17, 2005.
Abstract:	Following a brief history of radiocarbon work at EPA since the 1980's, the presentation focuses on recent non-winter measurements for PM-2.5 in the Southeastern U.S. (Houston, TX; Nashville, TN; and particularly, Tampa, FL) and what the measurements suggest about the importance of biogenic secondary organic aerosol (SOA) in this region. New measurements are also presented relating to the issue of bio-fuels (gasohol and biodiesel) and how their usage may affect the interpretation of future radiocarbon measurements.

PRESENTATION	A Fluorescence Based Assay for Dna Damage Induced By Toxic Industrial Chemicals	03/04/2005

KAILASAM, S. AND K. R. ROGERS. A Fluorescence Based Assay for Dna Damage Induced By Toxic Industrial Chemicals. Presented at Pittcon 2005, Orlando, FL, February 27 - March 04, 2005.
Abstract:	Numerous natural and man-made agents are continuously released into the environment due to human activity. Many of these agents cause irreversible damage to the normal biological functions leading to morbidity and mortality in the exposed organisms. The possibility of deliberate or accidental contamination in an industrial, commercial or residential setting has given rise to the need to monitor for the potential effects of hazardous chemicals in various environments. One of the reported effects for exposures to volatile and semi-volatile toxic industrial chemicals is DNA damage. The present study describes a simple and rapid assay based on changes in hybridization behavior of surrogate DNA to seven toxic industrial chemicals.

PRESENTATION	(Washington, Dc) a Fluorescence Based Assay for Dna Damage Induced By Toxic Industrial Chemicals	06/22/2005

ROGERS, K. R. AND S. KAILASAM. (Washington, Dc) a Fluorescence Based Assay for Dna Damage Induced By Toxic Industrial Chemicals. Presented at 2nd International Conference on Green and Sustainable Chemistry, Washington, DC, June 20 - 24, 2005.
Abstract:	Numerous natural and man-made agents are continuously released into the environment due to human activity. Many of these agents cause irreversible damage to the normal biological functions leading to morbidity and mortality in the exposed organisms. The possibility of deliberate or accidental contamination in an industrial, commercial or residential setting has given rise to the need to monitor for the potential effects of hazardous chemicals in various environments. One of the reported effects for exposures to volatile and semi-volatile toxic industrial chemicals is DNA damage. The present study describes a simple and rapid assay based on changes in hybridization behavior of surrogate DNA to seven toxic industrial chemicals.

PRESENTATION	A Fluorescence Based Assay for Dna Damage Induced By Toxic Industrial Chemicals	05/29/2005

KAILASAM, S. AND K. R. ROGERS. A Fluorescence Based Assay for Dna Damage Induced By Toxic Industrial Chemicals. Presented at American Chemical Society Meeting and Exposition, Washington, DC, August 28 - September 01, 2005.
Abstract:	One of the reported effects for exposure to many of the toxic industrial chemicals is DNA damage. The present study describes a simple, rapid and innovative assay to detect DNA damage resulting from exposure of surrogate DNA to toxic industrial chemicals (acrolein, allylamine, chloroacetone, formaldehyde, acrylonitrile, bromoethane, and crotonaldehyde) and nanomaterial (Buckminster fullerene). The assay is based on changes in the melting and annealing behavior observed for damaged DNA, which is monitored using a fluorescence indicator dye, PicoGreen .

PRESENTATION	Preliminary Findings from the Detroit Exposure and Aerosol Research Study (Dears)	03/02/2005

WILLIAMS, R. W., A. F. VETTE, C. W. CROGHAN, C. D. STEVENS, A. W. REA, D. A. WHITAKER, W. A. MCCLENNY, AND L. S. SHELDON. Preliminary Findings from the Detroit Exposure and Aerosol Research Study (Dears). Presented at 2nd Windsor Air Quality Symposium, Windsor, ON, CANADA, March 02, 2005.
Abstract:	The Detroit Exposure and Aerosol Research Study (DEARS) has completed its first monitoring season (summer 2005) and is progressing toward initiation of its second season (February 2005). The assistance obtained from the Michigan Department of Environmental Quality has been instrumental in this success as well as those of other collaborating institutions. This briefing will provide an overview of the study's goal and purposes, the research accomplishments to date and an understanding of current efforts to support the winter 2005 field monitoring effort. A preliminary report on summer 2004 monitoring efforts will be provided. These data indicate that: (1) the study was successful in the recruitment and retention of Wayne County residents during the 1st season, (2) the success of the study has been the result of continued cooperation between numerous governmental, academic, and private organizations, (3) an analysis of summer 2004 data indicates that the methodologies utilized in the monitoring would appear to be successful in detecting environmental analytes of interest, (4) fine particulate matter concentrations appear to have been homogeneous across the study area as indicative by mean concentrations normalized to those collected at Allen Park , and (5) a number of new collaboration efforts will be initiated during the winter 2005 monitoring season (such as the Healthy Heart Study). Although this work was reviewed by the EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Persistent Perfluorinated Organic Compounds	03/09/2005

STRYNAR, M. J. AND A. B. LINDSTROM. Persistent Perfluorinated Organic Compounds. Presented at LSU School of Public Health, New Orleans, LA, March 09, 2005.
Abstract:	Perfluorinated compounds (PFCs) have gained notoriety in the recent past. Global distribution of PFCs in wildlife, environmental samples and humans has sparked a recent increase in new investigations concerning PFCs. Historically PFCs have been used in a wide variety of consumer and industrial applications including paints, adhesives, surfactant, carpet/upholstery/paper coatings, and lubricants. The two most notable PFCs in this class of compounds are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Ongoing investigations by academia, private industry and government as to the fate, disposition and toxicity of these compounds are currently underway. This presentation will give an overview of PFC background information, current literature findings and activities at the U.S. Environmental Protection Agency ORD/HEASD/MDAB. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Methods to Evaluate Arsenic Bioavailability Associated With the Presence of Cca-Treated Wood Products	04/05/2005

BRADHAM, K. D., S. L. HARPER, E. A. COPPEDGE, R. KEYS, AND N. T. BASTA. Methods to Evaluate Arsenic Bioavailability Associated With the Presence of Cca-Treated Wood Products. Presented at 8th International Conference on the Biogeochemistry of Trace Elements, Adelaide, AUSTRALIA, April 03 - 07, 2005.
Abstract:	This is an invited paper to be presented by Dr. Karen Bradham at the 8th International Conference on the Biogeochemistry of Trace Elements, Adelaide, Australia, April 3 - 7, 2005. The abstract describes methods to evaluate arsenic bioavailability associated with the presence of CCA-treated wood products. The abstract describes the study design of projects currently being performed in NERL/HEASD and the methods used to evaluate arsenic bioavailability associated with the presence of CCA-treated wood products.

PRESENTATION	Assessing Carcinogenic Polycyclic Aromatic Hydrocarbons (PAH) Levels in the Aftermath of the New York World Trade Center Disaster	03/09/2005

PLEIL, J. D. Assessing Carcinogenic Polycyclic Aromatic Hydrocarbons (PAH) Levels in the Aftermath of the New York World Trade Center Disaster. Presented at School of PUblic Health, LSU Health Center, New Orleans, LA, March 09, 2005.
Abstract:	The catastrophic destruction of the World Trade Center (WTC) on Sept. 11, 2001 (9/11) created an immense dust cloud followed by fires that emitted smoke and soot into the air of New York City (NYC) well into December. Outdoor pollutant levels in lower Manhattan returned to urban background after about 100 to 200 days as the fires were put out and the debris cleanup was completed. However, particulate matter (PM) from the original collapse and fires also penetrated deeply into commercial and residential buildings where it continues to pose a re-exposure risk. Discriminating between "normal" urban pollutant infiltration and residual WTC dust remaining in the ventilation systems, common spaces, furnishings, and interior spaces (inside walls, closets, stairwells, etc.) is difficult. Some progress has been made in identifying WTC dust by content of fibers and metals, but this addresses only the initial building collapse. There is also concern over the effects of contaminants created by the fires burning for 100 days in the debris piles of the building rubble. Based on analyses of ambient air data, we have developed a candidate signature for WTC fire related PM based on the relative amounts of specific particle bound polycyclic aromatic hydrocarbons (PAHs) and have proposed a numerical parameter for assessing the likelihood that a given airborne or settled dust sample has WTC fires contribution. Furthermore, we demonstrate that the mass fraction of PAHs per mass of PM is related to the strength of the WTC component. These two parameters are combined and we propose a method for discriminating between fire sources and urban particulate sources to serve as a tool for assessing the WTC fires contribution to contemporary indoor dust. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency Policy.

PRESENTATION	Use of Exposure-Related Dose Estimating Model (Erdem) for Assessment of Aggregate Exposure of Infant and Children to N-Methyl Carbamate Insecticides	03/07/2005

POWER, F. W., J. B. KNAAK, M. S. OKINO, R. TORNERO-VELEZ, J. N. BLANCATO, AND C. C. DARY. Use of Exposure-Related Dose Estimating Model (Erdem) for Assessment of Aggregate Exposure of Infant and Children to N-Methyl Carbamate Insecticides. Presented at Society of Toxicology Annual Meeting, New Orleans, LA, March 06 - 10, 2005.
Abstract:	A physiologically based pharmacokinetic (PBPK) model was developed within the Exposure Related Dose Estimating Model (ERDEM) framework to investigate selected exposure inputs related to recognized exposure scenarios of infants and children to N-methyl carbamate pesticides as specified under the Food Quality Protection Act (FQPA). Conservative assumptions underlying residential exposure and cumulative risk were examined as inputs for particular exposure scenarios using residential dermal transfer coefficients, ambient air concentrations, and dietary intake. Physiological, pharmacokinetic and pharmacodynamic parameters describing the fate and effects of carbaryl, aldicarb, and propoxur in rats were scaled to establish the model structure for exposure to humans. Adjustments were made for differences in metabolism and physiology between children and adults. Michaelis-Menten kinetics were used to describe metabolism, where the chemical species compete for the catalytic enzymes. Bimolecular rate constants, ki (pM^-1 hr^-1), were used to describe inhibition of acetyicholinesterase by the parent compounds, where the effects are assumed to be additive. The simulation results over a day reveal the effects of residential exposure on cholinesterase activity, and highlight the scenarios and biological pathways where chemical interactions are important. The interactions are a cause for differences in risk between cumulative and single-chemical exposures. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Use of a Physiologically-Based Pharmacokinetic Model to Estimate Absorbed Carbaryl Dose in Children After Turf Application	03/09/2005

OKINO, M. S., F. W. POWER, J. B. KNAAK, R. TORNERO-VELEZ, C. LUNCHICK, A. LOWIT, J. N. BLANCATO, AND C. C. DARY. Use of a Physiologically-Based Pharmacokinetic Model to Estimate Absorbed Carbaryl Dose in Children After Turf Application. Presented at Socieity of Toxicology Annual Meeting, New Orleans, LA, March 06 - 10, 2005.
Abstract:	A physiologically based pharmacokinetic (PBPK) model was developed to investigate exposure scenarios of children to carbaryl following turf application. Physiological, pharmacokinetic and pharmacodynamic parameters describing the fate and effects of carbaryl in rats were scaled to establish the model structure for exposure to humans. Adjustments were made for differences in metabolism and physiology between children and adults. Michaelis-Menten kinetics were used to describe the metabolism of carbaryl to yield biomarkers of metabolism, including urinary 1-naphthol. Bimolecular rate constants, ki (pM^-1 hr^-1), were used to describe inhibition of acetylcholinesterase by the parent chemical. Rates for enzyme synthesis and reactivation were interposed within compartments to account for depletion of the enzymes. Exposure by hand-to-mouth activities for toddlers, and by dermal exposure for older children resulted in no observable cholinesterase inhibition (>99% of basal activity) in the brain and blood. Peak concentrations of carbaryl in the brain remained below the brain peaks observed in rats at the no observable adverse effect level (NOAEL) by an order-of-magnitude. Corresponding with the absorbed dose and subsequent distribution were the appearance of metabolite biomarkers in urine. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Characterizing Air Quality for Environmental Public Health Tracking	03/10/2005

WATKINS, T. H., D. M. HOLLAND, F. DIMMICK, L. TOOLY, E. BALDRIDGE, T. FITZ-SIMONS, D. MINTZ, AND B. COX. Characterizing Air Quality for Environmental Public Health Tracking. Presented at PHASE Team Meeting, Baltimore, MD, March 09 - 11, 2005.
Abstract:	This presentation provides a brief summary of EPA's perspective on Environmental Public Health Tracking, the Public Health Air Surveillance Evaluation (PHASE), and EPA's efforts to provide air quality data to three states (Maine, New York, and Wisconsin) that are partners with CDC National Environmental Public Health Tracking Program. The presentation includes a quantitative and qualitative analysis of the various air quality data sets the EPA provided to the CDC state partners for them to use in their analyses of potential air quality-public health relationships under the PHASE project.

PRESENTATION	Pharmacokinetic Evaluation of Perfluorooctanoic Acid in the Mouse	03/09/2005

LAU, C. S., M. J. STRYNAR, A. B. LINDSTROM, R. HANSON, J. R. THIBODEAUX, AND H. A. BARTON. Pharmacokinetic Evaluation of Perfluorooctanoic Acid in the Mouse. Presented at Society of Toxicology Meeting , New Orleans, LA, March 03 - 10, 2005.
Abstract:	The poster is a collaboration between NHEERL and NERL. The NERL researchers developed methods for the analyses of Perfluorooctanoic Acids (PFOA) in various animal tissue isolates. The NHEERL researchers are developing an appropriate animal model to assess the distribution and deposition of PFOA in humans and to facilitate extrapolations of potential risks. For this collaboration NERL developed methods for the analyses of these compounds in mouse tissue and serum. The resulting data will be used to create new and more appropriate model of PFOA distribution and fate in animal systems. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Quantitation of Organic Molecular Markers in Urban Particulate Matter from Philadelphia, Pa	06/22/2005

LI, M., S. R. MCDOW, D. J. TOLLERUD, AND M. A. MAZUREK. Quantitation of Organic Molecular Markers in Urban Particulate Matter from Philadelphia, Pa. Presented at Air & Waste Management Association 98th Annual Conference, Minneapolis, MN, June 21 - 24, 2005.
Abstract:	The purpose of this presentation is to present scientific results of a major organic aerosol analysis study at a national meeting.

PRESENTATION	Arsenic Bioavailability Associated With the Presence of Cca-Treated Wood Products	04/05/2005

BRADHAM, K. D., S. L. HARPER, E. A. COPPEDGE, AND N. T. BASTA. Arsenic Bioavailability Associated With the Presence of Cca-Treated Wood Products. Presented at 8th International Conference on the Biogeochemistry of Trace Elements, Adelaide, AUSTRALIA, April 05, 2005.
Abstract:	This is an invited paper/slide presentation to be presented by Dr. Karen Bradham at the 8th International Conference on the Biogeochemistry of Trace Elements, Adelaide, Australia, April 3 - 7, 2005. The PowerPoint slides describe the study design of projects currently being performed in NERL/HEASD and the methods used to evaluate arsenic bioavailability associated with the presence of CCA-treated wood products.

PRESENTATION	Exhaled Human Breath Measurement of Jet Fuel Constituents: Distinguishing Between Inhalation and Dermal Exposure Routes	05/27/2005

PLEIL, J. D., P. P. EGEGHY, E. CHAO, L. NYLANDER-FRENCH, AND S. M. RAPPAPORT. Exhaled Human Breath Measurement of Jet Fuel Constituents: Distinguishing Between Inhalation and Dermal Exposure Routes. Presented at Breathing Analysis for Medical Diagnosis and Therapeutic Monitoring, Innsbruck, AUSTRIA, May 26 - 28, 2005.
Abstract:	In response to anecdotal reports, perceived health issues, and widespread complaints, the U.S. military launched an investigation into the occupational and environmental human exposure to jet fuel. The work described in the presentation assesses the correlation between two breath measurement methods and interprets these results to predict the relative contribution from the inhalation and the dermal exposure pathways. We subsequently correlate these predictions with objective measures of dermal-only exposure as assessed via a skin tape stripping method. As such, we demonstrate the range of total jet fuel exposure for Air Force personnel, the dermal-only exposures, and also the utility of breath measurements to estimate the relative contribution of the dermal and inhalation exposure routes.

PRESENTATION	Recent Developments in Exhaled Breath Analysis and Human Exposure Assessment Research	05/27/2005

LINDSTROM, A. B. Recent Developments in Exhaled Breath Analysis and Human Exposure Assessment Research. Presented at Breath Analysis for Medical Diagnosis and Therapeutic Monitoring, Innsbruck, AUSTRIA, May 26 - 28, 2005.
Abstract:	This presentation will explore historical and newly emerging methods for the collection and analysis of exhaled breath for use in environmental exposure assessment studies. We will discuss their applicability and limitations with respect to environmental research. Particular emphasis will be placed on new methods and their utility for examining exhaled biomarkers of environmental pollution.

PRESENTATION	An Enzyme-Linked Immunosorbent Assay (ELISA) for Determining Dioxins in Sediment and Soil Samples	05/17/2005

VAN EMON, J. M., J. C. CHUANG, B. LORDO, M. NICHKOVA, S. J. GEE, AND B. HAMMOCK. An Enzyme-Linked Immunosorbent Assay (ELISA) for Determining Dioxins in Sediment and Soil Samples. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	The dioxins comprise a family of compounds chemically referred to as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The most toxic of these compounds is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a known human carcinogen. Dioxins are formed mainly as by-products of industrial processes (e.g., waste incineration) and can also be produced from natural processes (e.g., volcanic eruption or forest fire). Exposure to dioxins has been linked to various adverse health effects such as severe skin disease (chloracne), birth defects, and an increased risk of cancer. Non-occupational routes of exposure to dioxins include inhalation of contaminated air, ingestion of contaminated food and non-food items, and dermal contact. Conventional analytical methods for determining dioxins rely on sophisticated instrumentation, such as gas chromatographs and high resolution mass spectrometers. These methods are typically time consuming and costly, severely limiting the number of samples that can be processed. Low-cost field screening methods and efficient high-capacity laboratory methods are needed to support large-scale environmental monitoring and human exposure assessment studies. Immunoassays, such as the enzyme-linked immunosorbent assay (ELISA), use antibodies to analyze samples rapidly and cost effectively. An ELISA was developed at the University of California, Davis for the detection of various dioxins. More than 80 sediment and soil samples from a U.S. Environmental Protection Agency (U.S. EPA) Superfund site were analyzed by the ELISA and compared with an instrumental method. The findings suggest that the ELISA method can be used as a quantitative monitoring tool for determining dioxin levels in monitoring studies and to determine dioxin toxic equivalent values in environmental samples.

PRESENTATION	Partnering to Improve Human Exposure Methods	05/17/2005

MEDINA-VERA, M., S. L. HARPER, A. B. LINDSTROM, R. L. SEILA, AND J. M. STARR. Partnering to Improve Human Exposure Methods. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	Methods development research is an application-driven scientific area that addresses programmatic needs. The goals are to reduce measurement uncertainties, address data gaps, and improve existing analytical procedures for estimating human exposures. Partnerships have been developed across NERL, ORD, regions, program offices, and federal agencies to integrate research and maximize resources. Data produced by these methods are used to perform risk assessments, support regulatory decisions, and populate databases that inform the general public. Examples of NERL partnerships include: (1) Developing new methods for assessing exposures to chromated copper arsenate (CCA) with the National Risk Management Laboratory, the Office of Pesticide Programs (OPP), and the Consumer Product Safety Commission; (2) Collaboration on analytical methods for perfluorinated compounds with the National Health and Environmental Effects Research Laboratory (NHEERL) to support exposure data needs for the Office of Prevention, Pesticides, and Toxics; (3) Collaborations with Regions 3, 4 & 5 to provide tools to states and local governments for alkylphenols analyses and alternative methods to the current toxic organics methods; (4) State collaborations: Detroit Exposure and Aerosol Research Study integrates work among U.S. Environmental Protection Agency, Michigan Department of Environmental Quality, and the University of Michigan. Data will support development of a criteria document and human health protective standards for particulate matter (PM), components, and air toxics; (5) Nationwide collaborations: American Healthy Homes Survey (AHHS) is a collaboration among NERL, Office of Pollution Prevention and Toxics (OPPT), and the Office of Healthy Homes and Lead Hazard Control/U.S. Department of Housing and Urban Development (HUD) to perform a national survey of housing-related hazards. NERL provides exposure methods for analytes such as pesticides, perfluorinated compounds, and arsenic associated with the presence of CCA-treated wood. The data will be included in the first national residential multi-parameter database.

PRESENTATION	Formation Mechanisms for Secondary Organic Aerosol in Ambient Air	05/17/2005

KLEINDIENST, T. E., E. O. EDNEY, M. LEWANDOWSKI, J. H. OFFENBERG, M. JAOUI, AND J. SEINFELD. Formation Mechanisms for Secondary Organic Aerosol in Ambient Air. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	An laboratory and field research program is underway at the NERL to characterize secondary organic carbon in PM_2.5 which is formed through chemical reactions in the atmosphere. Information from this study will provide critical data needed to improve the treatment of SOA formation in the Community Multiscale Air Quality (CMAQ) model.

PRESENTATION	Ambient Ammonia Monitoring Technologies	05/17/2005

SUMNER, A. L., K. COWEN, A. DINDAL, K. RIGGS, J. HATFIELD, AND R. G. FUERST. Ambient Ammonia Monitoring Technologies. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	The Environmental Technology Verification (ETV) Program develops testing protocols and verifies the performance of innovative technologies that have the potential to improve the protection of human health and the environment. This abstract and poster describe the process by which those technologies are tested. Several companies participated in the testing of ammonia monitors and the results are shown in the poster.

PRESENTATION	Evaluating Risk in Older Adults Using Physiologically Based Pharmacokinetic Models	05/17/2005

OKINO, M. S., M. V. EVANS, S. ISUKAPALLI, S. WANG, P. G. GEORGOPOULOS, M. KARSTADT, R. TORNERO-VELEZ, M. DEVITO, L. S. BIRNBAUM, J. N. BLANCATO, AND A. M. GELLER. Evaluating Risk in Older Adults Using Physiologically Based Pharmacokinetic Models. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	The rapid growth in the number of older Americans has many implications for public health, including the need to better understand the risks posed by environmental exposures to older adults. An important element for evaluating risk is the understanding of the doses of environmental toxicants that reach potential target organs and how long these toxicants dwell in the body. While some data exist on the responses of older adults to therapeutic medications, there are broad data gaps in our understanding of the determinants of dosimetry to toxicants in this subpopulation. Researchers in the ORD's National Health and Environmental Effects Research Laboratory (NHEERL) and NERL are collaborating with the EOHSI, a joint project of UMDNJ and the R.W. Johnson Medical School and Rutgers University, to produce physiologically based pharmacokinetic (PBPK) models that mathematically describe the physiology of older individuals in the context of chemical absorption, distribution, metabolism, and excretion (ADME). The ORD researchers have extensive experience in developing and applying PBPK models toward human health risk assessment; the EOHSI brings advanced computational methods required to determine which changes in model parameters most affect tissue dosimetry and toxicity for prototype toxicants. The representation of the physiological and biochemical pathways with these models allows for the evaluation of changes to the risk metrics as the effects of aging are implemented in the model. These effects may include decline in renal function, changes in tissue composition, and changes to metabolic enzymes due to age, health status, or medications. PBPK models will be developed for a diverse set of chemicals relevant to the diverse population of older adults. This research will identify characteristics that are associated with enhanced risk in older adults. These results will be used to predict who in the older adult subpopulation may be most susceptible and which toxicants present the greatest risks based on known changes in pharmacokinetics with age, disease, pharmaceutical use, and diet. This work will also help to identify areas on which future research should be focused to efficiently reduce uncertainties in risk assessment.

PRESENTATION	Inhalation Exposure and Intake Dose Model Improvements	05/17/2005

GRAHAM, S. E., J. M. BURKE, T. R. MCCURDY, H. D. RICHMOND, AND J. LANGSTAFF. Inhalation Exposure and Intake Dose Model Improvements. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	This presentation highlights recent human exposure model improvements and products developed by the EMRB in coordination with scientists in the OAQPS and provides insight into how these products are used by the OAQPS in its regulatory process. Besides providing a status report of inhalation model developments and improvements, work planned to evaluate the performance and efficacy of the SHEDS and OAQPS models is also discussed. Findings from these model evaluation projects are expected to provide detailed guidance on future EMRB research planning and program development.

PRESENTATION	U.S. Environmental Protection Agency's PM Supersites Program a Major Successful Collaborative Air Quality Program Supporting States and Regional Organizations in Their Approaches to Reduce PM Levels in Air on Urban and Regional Scales	05/17/2005

SOLOMON, P. A. AND R. SCHEFFE. U.S. Environmental Protection Agency's PM Supersites Program a Major Successful Collaborative Air Quality Program Supporting States and Regional Organizations in Their Approaches to Reduce PM Levels in Air on Urban and Regional Scales. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	The U.S. Environmental Protection Agency's Particulate Matter (PM) Supersites Program (Program) is a nationwide air quality methods, measurement, modeling, and data analysis program initiated through cooperative agreements with leading universities in the United States. The Program provides state of the science information to support 1) the development of emission reduction strategies designed into State Implementation Plans (SIPs) by improving our understanding of PM_2.5 accumulation on urban and regional scales and relationships between sources and receptors, 2) human exposure and health effects research, and 3) development and testing of measurement methods for possible transition to national PM monitoring networks. Eight Supersites Projects were established in major cities across the U.S. covering areas of most concern with regards to PM pollution.

PRESENTATION	Partnering to Collect Improved Human Exposure Measurement Data	05/17/2005

TULVE, N. S., A. F. VETTE, R. C. FORTMANN, D. BARR, K. D. BRADHAM, R. BROOK, J. M. BURKE, C. CAVE, E. A. COPPEDGE, D. L. COSTA, C. W. CROGHAN, K. EDGREN, A. FRASER, W. FRIEDMAN, S. L. HARPER, M. HEINDORF, R. HIGHSMITH, A. HILLIARD, D. JONES, A. B. LINDSTROM, P. J. LIOY, D. MARKER, L. J. MELNYK, S. MUKERJEE, L. NAEHER, L. M. NEAS, M. NISHIOKA, A. W. REA, L. S. SHELDON, J. SMITH, C. D. STEVENS, D. STOUT, S. VEIT, A. WHEELER, D. A. WHITAKER, R. W. WILLIAMS, AND J. ZHOU. Partnering to Collect Improved Human Exposure Measurement Data. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	Partnering allows complex environmental challenges to be efficiently addressed by leveraging resources and scientific expertise. The US Environmental Protection Agency's Office of Research and Development (ORD) routinely collaborates with other federal, state, and local government organizations, as well as academia and international groups, to address research questions related to pesticide and particulate matter exposures in non-occupational environments. This abstract highlights four collaborations undertaken since 2001: JAX, CCC, DEARS, and AHHS.

PRESENTATION	The Agricultural Health Study: Collaborative Health and Exposure Research for the Agricultural Community	05/17/2005

THOMAS, K. W., R. ALLEN, D. SANDLER, A. BLAIR, J. HOPPIN, C. HINES, AND M. ALAVANJA. The Agricultural Health Study: Collaborative Health and Exposure Research for the Agricultural Community. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	The abstract describes the collaborative effort between the NCI, the NIEHS, the U.S. EPA, and NIOSH to conduct the Agricultural Health Study (AHS). The AHS is a prospective epidemiological study to identify factors that may affect the rate of cancer and other diseases among farmers and their families and factors that may promote health in the agricultural community. The U.S. EPA is leading a pesticide exposure measurement study to measure farm applicator exposures to applied pesticides and to assess and refine exposure classification procedures used by AHS epidemiologists.

PRESENTATION	Health and Environmental Sciences Institute's Exposure Factors Database for Aggregate and Cumulative Risk Assessment	05/17/2005

BERGERON, V., C. BRECKENRIDGE, J. DRIVER, J. EVANS, A. GOETZ, G. MIHLAN, D. MILLER, M. PANDIAN, S. PETTIT, S. RAMJI, D. SARGENT, W. D. SHADE, K. R. SOLOMON, T. THONGSINTHUSAK, N. S. TULVE, V. ZARTARIAN, D. VOGEL, AND J. ZABIK. Health and Environmental Sciences Institute's Exposure Factors Database for Aggregate and Cumulative Risk Assessment. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of input variables in the overall estimation of total exposure and risk to an individual person with demographic, geographic and temporal specificity. However, a risk assessor's ability to evaluate the validity of a model outcome is predicated on a clear understanding of the quality and variability associated with these input variables. As such, the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute's (HESI) Risk Assessment Methodologies Technical Committee (RAM Committee) identified the need for better characterization and electronic availability of public, non-chemical specific data sets for use in state-of-the-science aggregate residential exposure models. As a first step, the RAM Committee, in conjunction with infoscientific.com, Inc., has reviewed public data on micro- and macro-activity factors (e.g., mouthing behavior event frequencies, time spent on a residential lawn), and mass-transfer-related factors (e.g., surface-to-skin/clothing mass transfer, biological monitoring measurements following choreographed dermal exposure events, dermal transfer coefficients, and transfer removal efficiencies). These data were evaluated both qualitatively and quantitatively and organized in an electronic database with their associated meta information. The database and a guidance manual are available free to the public. Additional data, meta information, and guidance can be added to this database in the future. This effort provides important opportunities for collaboration and synergy with the EPA's Exposure Factors Handbook (general and child-specific) and regulatory agency exposure assessment methods development (e.g., EPA, Office of Pesticide Programs, Standard Operating Procedures for Residential Exposure Assessment). Additionally, the database was shared with representatives from "ExpoFacts" the European Exposure Factors database project. The HESI RAM Technical Committee, which designed and reviewed the database, is composed of representatives from academia, industry, and government.

PRESENTATION	Integration of Biomonitoring Exposure Data Into the Risk Assessment Process	05/17/2005

SHELDON, L. S., H. ZENICK, N. DOERRER, L. NEEDHAM, S. ROBINSON, AND E. FAUSTMAN. Integration of Biomonitoring Exposure Data Into the Risk Assessment Process. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	Improved biomonitoring techniques are being used to measure very low levels of environmental chemicals in the tissues of adults and children. Public and private demand for biomonitoring data are on the increase worldwide. In the United States alone, government-sponsored programs include the National Health and Nutrition Examination Survey (NHANES) conducted by the CDC, the CDC National Environmental Public Health Tracking Program, the Interagency National Children's Study, the Interagency Agricultural Health Study, the Farm Family Exposure Study, the pilot studies conducted by the U.S. Environmental Protection Agency (U.S. EPA) as part of the National Human Exposure Assessment Survey (NHEXAS), and the new project on Human Biomonitoring for Environmental Toxicants undertaken by the National Academy of Sciences.

PRESENTATION	Poster Title: Understanding Mercury Fate and Transport from Sources to Deposition	05/17/2005

LANDIS, M. S. Poster Title: Understanding Mercury Fate and Transport from Sources to Deposition. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	ORD's atmospheric mercury research produces information to improve the understanding of mercury transport and fate from the point of emission into the atmosphere to its deposition to terrestrial and aquatic ecosystems. Specifically, this research will produce source emission and atmospheric processes information to improve models that are used to predict atmospheric mercury deposition. These research results will be used to develop scientifically sound policies for mercury risk management.

PRESENTATION	Source Apportionment of Seattle PM 2.5 Using Stn Organic Carbon Peaks	10/18/2005

LARSON, T. V., E. KIM, AND G. A. NORRIS. Source Apportionment of Seattle PM 2.5 Using Stn Organic Carbon Peaks. Presented at 24th Annual American Association for Aerosol Research Conference, Austin, TX, October 17 - 21, 2005.
Abstract:	Results from the Source Apportionment of Seattle PM_2.5 Using STN Organic Carbon Peaks study will be presented at the American Association for Aerosol Research (AAAR) 24th Annual Conference in Austin, Texas (Oct 17 - 21, 2005). Receptor modeling results from Seattle using both STN and IMPROVE thermal optical analysis carbon peak data will be discussed.

PRESENTATION	Combined Receptor Model for Ambient and Personal Exposure Samples	10/18/2005

ZHAO, W., P. K. HOPKE, AND G. A. NORRIS. Combined Receptor Model for Ambient and Personal Exposure Samples. Presented at 24th Annual American Association for Aerosol Research Conference, Austin, TX, October 17 - 21, 2005.
Abstract:	Results from the Combined Receptor Model for Ambient and Personal Exposure Samples analysis will be presented at the American Association for Aerosol Research (AAAR) 24th Annual Conference in Austin, Texas (Oct 17 - 21, 2005). Receptor modeling approaches and results from EPA Research Triangle Park Human Exposure study will be discussed.

PRESENTATION	Understanding Mercury Fate and Transport from Sources to Deposition	05/17/2005

LANDIS, M. S. AND T. H. WATKINS. Understanding Mercury Fate and Transport from Sources to Deposition. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	ORD's atmospheric mercury research produces information to improve the understanding of mercury transport and fate from the point of emission into the atmosphere to its deposition to terrestrial and aquatic ecosystems. Specifically, this research will produce source emission and atmospheric processes information to improve models that are used to predict atmospheric mercury deposition. These research results will be used to develop scientifically sound policies for mercury risk management.

PRESENTATION	The Detroit Children's Health Study: An Examination of the Effects of Ambient Air Exposure on the Respiratory Health of Asthmatic Children	05/17/2005

WILLIAMS, A. H., G. ANDREWS, S. MUKERJEE, AND L. M. NEAS. The Detroit Children's Health Study: An Examination of the Effects of Ambient Air Exposure on the Respiratory Health of Asthmatic Children. Presented at EPA Science Forum 2005, Washington, DC, May 16 - 18, 2005.
Abstract:	The United States has experienced a significant increase in childhood asthma since the late 1980s. EPA's Office of Children's Health Protection estimates that one out of every fifteen children under 18 years of age has asthma. In children under 5 years of age, asthma rates have increased 160 percent in the past 18 years. The Detroit Children's Health Study (DCHS) will examine the question of whether long-term, early-life exposures to emissions from traffic and other urban sources play a key role in the development and aggravation of allergic asthma in schoolchildren. Scientists from EPA's National Health and Environmental Effects Research Laboratory (NHEERL), carrying out the epidemiologic and respiratory health study, are collaborating with those of EPA's National Exposure Research Laboratory (NERL) to conduct an exposure assessment of air in the Detroit area. The study will aid in the further development of an Air Quality Criteria for Particulate Matter under the Clean Air Act (42 U.S.C. 7403(d)).

PRESENTATION	Laboratory and Field Evaluation of Instrumentation for the Semi-Continuous Determination of Water-Soluble Particulate Components and Gases	05/18/2005

LONG, R. W. Laboratory and Field Evaluation of Instrumentation for the Semi-Continuous Determination of Water-Soluble Particulate Components and Gases. Presented at University of South Florida, Tampa, FL, May 18, 2005.
Abstract:	Studies conducted at the EPA facility in Research Triangle Park, NC and at a field study in Southern California have demonstrated the capability for the semi-continuous determination of water-soluble particulate components and gases. First, two instruments, a R&P 8400N particulate nitrate monitor and an ion chromatography (IC)-based prototype monitor developed at Texas Tech University (TTU), were evaluated both in the laboratory using simulated ambient aerosols and in the field (Rubidoux, CA) during a three week joint ambient comparison study with Brigham Young University (BYU) and the South Coast Air Quality Monitoring District (SCAQMD). During both the laboratory and field studies, both instruments were responsive to changes in the simulated aerosol concentration. However, potential problems were discovered involving both instruments. Second, a newly commercialized IC-based instrument for the determination of water-soluble particulate components and gases was extensively evaluated in a laboratory setting using simulated and indoor aerosols and gases. Results from the laboratory evaluations and field study will be addressed.

PRESENTATION	Exposure Assessment of Older Adults to Particulate Matter	06/15/2005

WILLIAMS, R. W. Exposure Assessment of Older Adults to Particulate Matter. Presented at Mickey Leland National Urban Air Toxics Research Center Symposium, Arlington, VA, June 14 - 15, 2005.
Abstract:	The factors that influence the amount of particulate matter that potentially susceptible elderly Americans are exposed to is an issue of concern. This presentation and abstract investigates these factors using data obtained from three longitudinal particulate matter panel studies performed by the US EPA. Findings indicate that factors such as housing and personal activities can greatly influence one's total personal exposure and more importantly one's exposure to particulate matter of ambient origin.

PRESENTATION	Data Collected in the EPA National Exposure Research Laboratory Human Exposure Measurement Program to Evaluate Children's Aggregate Exposure to Pesticides	05/19/2005

TULVE, N. S., R. C. FORTMANN, AND L. S. SHELDON. Data Collected in the EPA National Exposure Research Laboratory Human Exposure Measurement Program to Evaluate Children's Aggregate Exposure to Pesticides. Presented at Twenty-Second Triangle Chromatography Symposium and Instrument Exhibit, Raleigh, NC, May 19, 2005.
Abstract:	Data collected in the human exposure measurement program protocol for measuring children's non-occupational exposures inhalation, dermal, indirect, ingestion exposures and activity patterns.

PRESENTATION	Emerging Science: EPA's Ord Supports Regional Haze Program; Posters from Bosc Review and Science Forum	06/09/2005

DIMMICK, F. Emerging Science: EPA's Ord Supports Regional Haze Program; Posters from Bosc Review and Science Forum. Presented at Regional Planning Organization, Denver, CO, June 09 - 10, 2005.
Abstract:	A series of presentations from EPA's Board of Science Councilors review in April 2005 and the Science Forum in May 2005 are being made available to the Regional Planning Organization conference on June 9-10, 2005. Attendees will be able to review the materials during the conference, learning about ORD research into atmospheric sciences. An overview presentation is being made to introduce the topic to the conference.

PRESENTATION	Emerging Science: EPA's Ord Supports Regional Haze Program	06/09/2005

DIMMICK, F. Emerging Science: EPA's Ord Supports Regional Haze Program. Presented at RPO National Technical Meeting, Denver, CO, June 09 - 10, 2005.
Abstract:	A series of presentations from EPA's Board of Science Councilors review in April 2005 and the Science Forum in May 2005 are being made available to the Regional Planning Organization conference on June 9-10, 2005. Attendees will be able to review the materials during the conference, learning about ORD research into atmospheric sciences. An overview presentation is being made to introduce the topic to the conference.

PRESENTATION	Perfluorinated Compounds in Archived House-Dust Samples	08/19/2005

STRYNAR, M. J. AND A. B. LINDSTROM. Perfluorinated Compounds in Archived House-Dust Samples. Presented at FLUOROS 2005, Toronto, BC, CANADA, August 18 - 20, 2005.
Abstract:	Archived house-dust samples were analyzed for 13 perfluorinated compounds (PFCs). Results show that PFCs are found in house-dust samples, and the data are log-normally distributed. PFOS/PFOA were present in 94.6% and 96.4% of the samples respectively. Concentrations ranged from below the limit of quantitation (~0.1 µg/g) to a maximum of 357 µg/g (PFHS).

PRESENTATION	Pregnancy Loss Associated With Exposure to Perfluorooctanoic Acid in the Mouse	06/27/2005

LAU, C. S., J. R. THIBODEAUX, L. THAI, R. HANSON, M. R. BLANTON, E. S. HUNTER, B. D. ABBOTT, AND M. J. STRYNAR. Pregnancy Loss Associated With Exposure to Perfluorooctanoic Acid in the Mouse. Presented at 45th Annual Teratology Society Meeting, St Pete Beach, FL, June 25 - 30, 2005.
Abstract:	Pregnancy loss in the mouse due to perfluorooctanoic acids (PFOA) was investigated in this present study. Daily administration of PFOA (20 or 40 mg/kg) by oral gavage to pregnant CD-1 mice from GD 1-17 led to 75% and 100% incidence respectively, of total resorption at term with corresponding maternal serum PFOA levels of 0.18 mg/ml and 0.27 mg/ml. In vitro mouse embryos exposed to PFOA greater than 0.4 mg/mL led to significant changes in embryo morphology with 1.25 mg/mL leading to 100 percent embryolethality.

PRESENTATION	Measurement of Pyrethroid Residues in Environmental and Food Samples By Enhanced Solvent Extraction/Supercritical Fluid Extraction Coupled With Gas Chromatography-Tandem Mass Spectrometry	08/30/2005

XIONG, G. AND J. M. VAN EMON. Measurement of Pyrethroid Residues in Environmental and Food Samples By Enhanced Solvent Extraction/Supercritical Fluid Extraction Coupled With Gas Chromatography-Tandem Mass Spectrometry. Presented at American Chemical Society Meeting and Exposition , Washington, DC, August 28 - September 01, 2005.
Abstract:	The abstract summarizes pyrethorid methods development research. It provides a summary of sample preparation and analytical techniques such as supercritical fluid extraction, enhance solvent extraction, gas chromatography and tandem mass spectrometry.

PRESENTATION	Indoor Air Concentrations of Organochlorine, Organophosphate and Pyrethroid Pesticides in the US: Four Studies, Six States and Twenty Years	08/24/2005

STOUT, D. M. AND P. P. EGEGHY. Indoor Air Concentrations of Organochlorine, Organophosphate and Pyrethroid Pesticides in the US: Four Studies, Six States and Twenty Years. Presented at Dioxin 2005, Toronto, ON, CANADA, August 21 - 26, 2005.
Abstract:	Pesticides used to control indoor pests have transitioned across the chemicals classes of organochlorine, organophosphate, and pyrethroid compounds from the 1980's to the present. This work summarizes the pesticide concentrations measured from the indoor air of homes from four studies sponsored by the US EPA. The frequency of detection varied across studies with an increased frequency of detection over time that is likely influenced by improved detection limits. Pesticides were commonly measured in all studies. Mean concentrations show highly variable heptachlor levels, while chlordane appears to decline from 1988 levels. DDT and DDE show little difference over time. All organophosphate concentrations were lower than those measured in the NOPES-FL. Permethrin concentrations were variable and none was measured in NOPES-MA. Findings demonstrate the high degree of variability across studies associated with indoor air concentrations measured from homes. There is a suggestion of decreasing concentrations for some pesticides. Finally, comparability between studies would be improved by routinely performing studies in the same cities or states.

PRESENTATION	The Nist-EPA Interagency Agreement on Measurements and Standards in Aerosol Carbon: Sampling Regional PM 2.5 for the Chemometric Optimization of Thermal-Optical Analysis	10/18/2005

CONNY, J. M. AND G. A. NORRIS. The Nist-EPA Interagency Agreement on Measurements and Standards in Aerosol Carbon: Sampling Regional PM 2.5 for the Chemometric Optimization of Thermal-Optical Analysis. Presented at 24th Annual American Association for Aerosol Research Conference, Austin, TX, October 17 - 21, 2005.
Abstract:	Results from the NIST-EPA Interagency Agreement on Measurements and Standards in Aerosol Carbon: Sampling Regional PM2.5 for the Chemometric Optimization of Thermal-Optical Analysis Study will be presented at the American Association for Aerosol Research (AAAR) 24th Annual Conference in Austin, Texas (Oct 17 - 21, 2005). The poster will discuss the optimization of the Thermal Optical Analysis particulate matter organic and elemental carbon protocol using secondary aerosol, motor vehicle, and wood smoke impacted samples.

PRESENTATION	Understanding Systematic Measurement Error in Thermal-Optical Analysis for PM Black Carbon Using Response Surfaces and Surface Confidence Intervals	10/18/2005

CONNY, J. M., G. A. KLOUDA, G. A. NORRIS, AND D. A. OLSON. Understanding Systematic Measurement Error in Thermal-Optical Analysis for PM Black Carbon Using Response Surfaces and Surface Confidence Intervals. Presented at 24th Annual American Association for Aerosol Research Conference, Austin, TX, October 17 - 21, 2005.
Abstract:	Results from a NIST-EPA Interagency Agreement on Understanding Systematic Measurement Error in Thermal-Optical Analysis for PM Black Carbon Using Response Surfaces and Surface Confidence Intervals will be presented at the American Association for Aerosol Research (AAAR) 24th Annual Conference in Austin, Texas (Oct 17 - 21, 2005). The presentation will discuss the use of response surface models to provide unique insights into the behavior of thermal-optical particulate organic and elemental carbon instruments.

PRESENTATION	Determination of 2-Methyl Tetrols and 2-Methylglyceric Acid in Secondary Organic Aerosol from Laboratory Irradiated Isoprene/No _x/So ₂/Air Mixtures	08/30/2005

KLEINDIENST, T. E., E. O. EDNEY, M. LEWANDOWSKI, J. H. OFFENBERG, M. JAOUI, W. WANG, AND M. CLAEYS. Determination of 2-Methyl Tetrols and 2-Methylglyceric Acid in Secondary Organic Aerosol from Laboratory Irradiated Isoprene/No _x/So ₂/Air Mixtures. Presented at European Aerosol Conference, Ghent, BELGIUM, August 28 - September 02, 2005.
Abstract:	This presentation addresses recent work performed at EPA to evaluate the potential for the photooxidation of isoprene to produce secondary organic aerosol. Analysis of the samples for methyl tetrols and 2-methylglyceric acid were performed at EPA and the University of Antwerp. The presence of sulfur dioxide in the laboratory irradiations substantially enhanced the formation of secondary organic aerosol.

PRESENTATION	Mathematical Manipulations of Enantiomeric Data	08/29/2005

ULRICH, E. M., D. R. HELSEL, AND W. T. FOREMAN. Mathematical Manipulations of Enantiomeric Data. Presented at American Chemical Society Meeting and Exposition, Washington, DC, August 28 - September 01, 2005.
Abstract:	The oral presentation describes the alternative method of peak fitting for the measurement of enantiomeric parameters such as enantiomeric ratio (ER) and enantiomer fraction (EF). The talk describes the disadvantage of using typical integrators, mathematical calculations such as average of a group of samples, the impact of ratio functions, and average ERs to the EF scale conversions. It also highlights the advantage of the peak fitting method which minimizes analyst bias.

PRESENTATION	Effects of Polycyclic Aromatic Hydrocarbon of Sam-Coated Electrodes Using Ferryicyanide as the Redox Indicator	08/29/2005

LUO, N., D. W. HATCHETT, AND K. R. ROGERS. Effects of Polycyclic Aromatic Hydrocarbon of Sam-Coated Electrodes Using Ferryicyanide as the Redox Indicator. Presented at American Chemical Society Meeting and Exposition, Washington, DC, August 28 - September 01, 2005.
Abstract:	Electrochemical responses on self-assembled monolayer (SAM)-coated polycrystalline gold electrodes were investigated using cyclic voltammetry and square wave voltammetry with a three electrode system. Experimental results show potential in the application of pyrene-imprinted SAMs for sensors of polycyclic aromatic hydrocarbons.

PRESENTATION	Relating Air Quality and Environmental Public Health Tracking Data	10/06/2005

BOOTHE, V., F. DIMMICK, AND T. O. TALBOT. Relating Air Quality and Environmental Public Health Tracking Data. Presented at First International Conference on Environmental Exposure and Health, Atlanta, GA, October 05 - 07, 2005.
Abstract:	Initiated in February 2004, the Public Health Air Surveillance Evaluation (PHASE) Project is a multi-disciplinary collaboration between the Centers for Disease Control and Prevention (CDC), the U.S Environmental Protection Agency (EPA), and three Environmental Public Health Tracking Network (EPHTN) state agencies. The objective of this project is to develop, evaluate, and demonstrate the advantages and limitations of different methods of generating air quality characterization data that could be systematically and routinely available to link with public health surveillance data as part of the Environmental Public Health Tracking Network.

PRESENTATION	Spatial and Temporal Variability in Acrolein and Select Volatile Organic Compounds in Detroit, Michigan	07/27/2005

GOLDMAN, G., C. W. CROGHAN, P. P. EGEGHY, AND A. F. VETTE. Spatial and Temporal Variability in Acrolein and Select Volatile Organic Compounds in Detroit, Michigan. Presented at NIEHS Summer of Discovery Poster Session, Research Triangle Park, NC, July 27, 2005.
Abstract:	The variability in outdoor concentrations of acrolein, benzene, toluene, ethylbenzene and xylenes (BTEX), and 1,3-butadiene was examined for data measured during summer 2004 of the Detroit Exposure and Aerosol Research Study (DEARS). Results for acrolein indicated no significant spatial variability across the sampling domain, however, significant temporal variability was observed. Concentrations of benzene, toluene, and 1,3-butadiene showed significant spatial variability, where concentrations at the urban sites were generally twice as high as the rural monitoring site.

PRESENTATION	Using ¹⁴ C Methodology in Smog Chamber Research	09/07/2005

LEWIS, C. W., T. E. KLEINDIENST, M. LEWANDOWSKI, J. H. OFFENBERG, M. JAOUI, AND E. O. EDNEY. Using ¹⁴ C Methodology in Smog Chamber Research. Presented at 10th International Conference on Accelerarot Mass Spectrometry, Berkeley, CA, September 05 - 10, 2005.
Abstract:	Smog chambers are large enclosures (~ 10-200 m³) that are used to perform laboratory simulations of atmospheric reactions. By dealing with simple systems in which the number of reactants is limited and the conditions are strictly controlled, insights on how reactions proceed may be more easily realized than with real-world observations that are uncontrolled and inherently much more complex to analyze. A major focus of smog chamber research is the generation of secondary organic aerosol (SOA) that results from the reaction of gaseous hydrocarbons and inorganics (NOx) in the presence of simulated solar radiation. Of special interest is the relative SOA contribution of natural vs. anthropogenic hydrocarbon species. While until now methods have been developed to measure total SOA from such mixtures, very limited success has been achieved in determining the contribution from the individual hydrocarbons. However by arranging that the two hydrocarbons have different fractions of modern carbon and by measuring the fraction of modern carbon in the resulting SOA, the separate contributions of the two hydrocarbons may be readily calculated. These results can be compared to an alternative approach using GC-MS measurements of organic tracer compounds. A description of the experiment and results will be given, along with a discussion of potential distorting effects and their minimization.

PRESENTATION	Estimation of Adipose Tissue; Blood Partition Coefficients of Carbamates and Organophosphorus Pesticides Using Relative Lipid Content and Logp as the Mechanistic Determinants	08/31/2005

KNAAK, J. B., D. CHANG, C. C. DARY, R. TORNERO-VELEZ, M. S. OKINO, AND F. W. POWER. Estimation of Adipose Tissue; Blood Partition Coefficients of Carbamates and Organophosphorus Pesticides Using Relative Lipid Content and Logp as the Mechanistic Determinants. Presented at American Chemical Society Meeting and Exposition, Washington, DC, August 27 - September 01, 2005.
Abstract:	PBPK/PD models were developed for carbamate and OP pesticides to aid in human risk assessments.

PRESENTATION	Exposures of 127 Ohio Preschool Children to cis-and trans-Permethrin in Their Everyday Environments	11/02/2005

MORGAN, M. K., L. S. SHELDON, C. W. CROGHAN, P. A. JONES, J. C. CHUANG, AND N. K. WILSON. Exposures of 127 Ohio Preschool Children to cis-and trans-Permethrin in Their Everyday Environments. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	This study investigated the aggregate exposures of 257 preschool children to chemicals commonly found in their everyday environments. Participants were recruited randomly from selected homes and daycare centers in six North Carolina and six Ohio counties. Monitoring was performed over a 48-h period at the children's homes and/or daycare centers. Samples that were collected consisted of soil, dust, air, diet, dermal wipes, surface wipes, and urine. Environmental samples were analyzed by gas chromatography/mass spectrometry (GC/MS) for over 50 chemicals including the pyrethroid insecticide isomers, cis- and trans-permethrin. Urine samples were analyzed by GC/MS for several biomarkers of exposure including the non-specific urinary biomarker of exposure to the pyrethroids, 3-phenoxybenzoic acid (3-PBA). We report the preliminary results for the exposures of 127 Ohio preschool children to cis- and trans-permethrin at their homes and daycare centers. The isomers were detected in nine different media and were found most often in dust (100%) and hand wipe (> 78%) samples at both locations. The metabolite, 3-PBA, was detected in 59% of the children's urine samples. The median urinary 3-PBA concentration for these children was 0.3 ng/mL, and the maximum concentration was 33.8 ng/mL. Through inhalation, ingestion, and dermal routes of exposure, the median aggregate potential absorbed doses of cis- and trans-permethrin for these children were estimated at 2.1 and 1.7 ng/kg/day, respectively. The dominant route of exposure for both isomers was through dietary ingestion, followed by indirect ingestion. The median excreted amount of 3-PBA in the children's urine was estimated at 6.2 ng/kg/day. The results showed that these children were potentially exposed to both cis- and trans-permethrin from several sources, and through several pathways and routes. The urinary biomarker of exposure, 3-PBA, confirms that these children were exposed to and absorbed one or more of the pyrethroids, likely including permethrin, into their bodies. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Characterizing Air Quality for Environmental Public Health	10/25/2005

DIMMICK, F., D. M. HOLLAND, L. TOOLY, T. FITZ-SIMONS, D. MINTZ, B. COX, AND E. BALDRIDGE. Characterizing Air Quality for Environmental Public Health. Presented at Environmental Public Health Tracking Workshop, Tampa, FL, October 25, 2005.
Abstract:	NERL's Human Exposure and Atmospheric Sciences Division and other participants in the Public Health Air Surveillance Evaluation (PHASE) project will be presenting their results to the Environmnetal Public Health Tracking (EPHT) workshop in Tampa FL. The PHASE project is a collaboration between the EPA, CDC and the States of Maine, New York and Wisconsin. The objective of this collaboration is to develop, evaluate, and demonstrate the advantages and limitations of different methods of generating air quality characterization surveillance data that could be systematically and routinely available to link with public health surveillance data as part of the CDC's Environmental Public Health Tracking Network. EPA has provided air quality data for ozone and fine particles based on ambient air monitors, an application of the EPA/NOAA Community Multiscale Air Quality model, and statistically developed estimates.

PRESENTATION	Development and Evaluation of An Improved Soa Representation in the Cmaq Model	09/27/2005

OFFENBERG, J. H., E. O. EDNEY, T. KLEINDIENST, M. LEWANDOWSKI, M. JAOUI, P. BHAVE, C. NOLTE, AND G. SARWAR. Development and Evaluation of An Improved Soa Representation in the Cmaq Model. Presented at 4th Annual CMAS Models-3 User's Conference, Chapel Hill, NC, September 26 - 28, 2005.
Abstract:	This poster outlines ongoing laboratory and field work being performed to a) identify the major SOA precursors b) identify tracer compounds for the major SOA precursors and c) determine reaction mechanisms for SOA formation. The goal of this work is to incorporate newly-developed SOA formation mechanisms into the CMAQ model and to evaluate SOA chemistry models in CMAQ by comparing measured SOA concentrations with model predictions.

PRESENTATION	Integration of Satellite-Derived Aerosol Data Into the Air Quality Applications	10/19/2005

DIMMICK, F. Integration of Satellite-Derived Aerosol Data Into the Air Quality Applications. Presented at American Association for Aerosol Research, Austin, TX, October 17 - 21, 2005.
Abstract:	Historically, the only source of aerosol air quality data available on an ongoing and systematic basis at national levels was generated by ambient air monitoring networks put in place for the US EPA's Air Quality Programs. Over the past several years, the remote sensing of aerosols from space has improved dramatically. The emergence and application of these measurements adds a new dimension to air quality by enabling consistent observations of pollutants over large spatial domains. This talk will highlight some current air quality and public health prototype applications of satellite derived aerosol data sets by EPA.

PRESENTATION	An Integrated Synthesis of Key and Policy Relevant Findings from EPA's Supersites Program and Related Studies	10/18/2005

SOLOMON, P. A., P. K. HOPKE, AND J. R. FROINES. An Integrated Synthesis of Key and Policy Relevant Findings from EPA's Supersites Program and Related Studies. Presented at 24th Annual AAAR Conference, Austin, TX, October 17 - 21, 2005.
Abstract:	This presentation provides an overview and initial insights into the findings based on results from EPA's PM Supersites Program and related studies. Many key atmospheric sciences findings have been identified through the research conducted during the last five years as part of the Supersites Program. Many also have findings that are policy relevant (potentially impacting state and EPA decisions regarding regulations and implementation of current and future standards) and health relevant, both of which may be able to provide insights on these subjects to the policy and health communities. A summary of the approach to the synthesis is provided and then one key finding is described that follows the process from methods development to health and policy relevant findings.

PRESENTATION	Absence of ¹⁴c in PM _2.5 Emissions from Gasohol Combustion in Small Engines	10/19/2005

LEWIS, C. W., J. VOLCKENS, J. N. BRADDOCK, W. S. CREWS, AND W. A. LONNEMAN. Absence of ¹⁴c in PM _2.5 Emissions from Gasohol Combustion in Small Engines. Presented at 24th Annual Annual Conference of the American Association of Aerosol Research, Austin, TX, October 17 - 21, 2005.
Abstract:	The amounts of C^-14 measured in PM_2.5 emissions samples from small engines using gasohol (10% ethanol + 90% gasoline), were much less than that present in the fuel. This suggests that the current method of using C^-14 measurements on ambient samples to estimate the contribution from fossil fuel combustion will be little affected by increased use of gasohol.

PRESENTATION	(Detroit) Spatial Analysis of Summer 2004 Data from Dears	10/21/2005

JONES, P. A., C. W. CROGHAN, A. F. VETTE, AND R. W. WILLIAMS. (Detroit) Spatial Analysis of Summer 2004 Data from Dears. Presented at US-Canadian Detroit/Windsor Scientist to Scientist Workshop, Detroit, MI, October 21, 2005.
Abstract:	The Detroit Exposure and Aerosol Research Study (DEARS) represents a multi-year assessment field study involving summer and winter season collection of personal, residential indoor, residential outdoor and central community monitoring measurements.

PRESENTATION	(Tucson, Az) Spatial Analysis of Summer 2004 Data from Dears	10/31/2005

JONES, P. A., C. W. CROGHAN, A. F. VETTE, AND R. W. WILLIAMS. (Tucson, Az) Spatial Analysis of Summer 2004 Data from Dears. Presented at 2005 ISEA, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The Detroit Exposure and Aerosol Research Study (DEARS) represents a multi-year assessment field study involving summer and winter season collection of personal, residential indoor, residential outdoor and central community monitoring measurements.

PRESENTATION	Molecular Marker Analysis of Dears Samples	10/21/2005

MCDOW, S. R., D. A. OLSON, L. STOCKBURGER, AND J. TURLINGTON. Molecular Marker Analysis of Dears Samples. Presented at 2005 Detroit/Windsor Research Studies Meeting, Detroit, MI, October 21, 2005.
Abstract:	Source apportionment based on organic molecular markers provides a promising approach for meeting the Detroit Exposure and Aerosol Research Study (DEARS) objective of comparing source contributions between community air monitoring stations and various neighborhoods. Source apportionment of ambient particulate matter has been frequently achieved by comparing its elemental composition to major source emissions. This approach is difficult if sources are dominated by organic species, as for automobiles, biomass burning, and commercial cooking. For these sources, organic molecular markers such as polycyclic aromatic hydrocarbons, hopanes, unsaturated fatty acids, alkanes, and pyrolyzed sugars provide a more suitable alternative to elemental composition. Their recent measurement in major sources has led to several successful molecular marker based source apportionment efforts for ambient particulate matter. The greatest challenge for micro-environmental neighborhood samples is the high sensitivity required. In all previous ambient studies, samples were collected at relatively high flow rates and composited for extraction and analysis. A Tisch TE-1202 sampler widely used for molecular marker sample collection is in use at the air monitoring station. However, for micro-environmental samples flow rates are lower than in previous studies, but daily concentrations are still desired to adequately represent temporal variability. To increase sensitivity, a high volume injection method was implemented for analysis by gas chromatography/mass spectrometry. Highly linear calibrations were obtained with detection limits below 20 pg/m³ for all markers for low volume 24-hour samples. Recoveries of greater than 85% were obtained for high pressure solvent extraction of all molecular markers. Preliminary tests to verify that molecular markers can be detected in actual samples of smaller than 200 micrograms particulate mass are in progress. Preliminary results from the community air monitoring station will be presented. Performance of the high volume injection method will be described using preliminary results from other studies. Preliminary information on marker concentrations, potential source contributions, and method performance will be used to evaluate the use of molecular markers for comparing source contributions between the monitoring station and neighborhood samples. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	(Isea) Molecular Marker Analysis of Dears Samples	11/01/2005

MCDOW, S. R., D. A. OLSON, L. STOCKBURGER, AND J. TURLINGTON. (Isea) Molecular Marker Analysis of Dears Samples. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Source apportionment based on organic molecular markers provides a promising approach for meeting the Detroit Exposure and Aerosol Research Study (DEARS) objective of comparing source contributions between community air monitoring stations and various neighborhoods. Source apportionment of ambient particulate matter has been frequently achieved by comparing its elemental composition to major source emissions. This approach is difficult if sources are dominated by organic species, as for automobiles, biomass burning, and commercial cooking. For these sources, organic molecular markers such as polycyclic aromatic hydrocarbons, hopanes, unsaturated fatty acids, alkanes, and pyrolyzed sugars provide a more suitable alternative to elemental composition. Their recent measurement in major sources has led to several successful molecular marker based source apportionment efforts for ambient particulate matter. The greatest challenge for micro-environmental neighborhood samples is the high sensitivity required. In all previous ambient studies, samples were collected at relatively high flow rates and composited for extraction and analysis. A Tisch TE-1202 sampler widely used for molecular marker sample collection is in use at the air monitoring station. However, for micro-environmental samples flow rates are lower than in previous studies, but daily concentrations are still desired to adequately represent temporal variability. To increase sensitivity, a high volume injection method was implemented for analysis by gas chromatography/mass spectrometry. Highly linear calibrations were obtained with detection limits below 20 pg/m³ for all markers for low volume 24-hour samples. Recoveries of greater than 85% were obtained for high pressure solvent extraction of all molecular markers. Preliminary tests to verify that molecular markers can be detected in actual samples of smaller than 200 micrograms particulate mass are in progress. Preliminary results from the community air monitoring station will be presented. Performance of the high volume injection method will be described using preliminary results from other studies. Preliminary information on marker concentrations, potential source contributions, and method performance will be used to evaluate the use of molecular markers for comparing source contributions between the monitoring station and neighborhood samples. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	CONCENTRATIONS OF PARTICULATE ORGANIC SPECIES MEASURED IN INDOOR AND OUTDOOR ENVIRONMENTS DURING THE TAMPA ASTHMATIC CHILDREN'S STUDY ( TACS )	10/20/2005

OLSON, D. A., S. R. MCDOW, R. W. WILLIAMS, C. D. STEVENS, AND J. TURLINGTON. CONCENTRATIONS OF PARTICULATE ORGANIC SPECIES MEASURED IN INDOOR AND OUTDOOR ENVIRONMENTS DURING THE TAMPA ASTHMATIC CHILDREN'S STUDY ( TACS ). Presented at 24 Annual Conference, American Association for Aerosol Research, Austin, TX, October 17 - 21, 2005.
Abstract:	The Tampa Asthmatic Children's Study (TACS) was completed to assess environmental exposures for a group of asthmatic children (n = 9) under the age of six and living in Tampa, Florida. Concentrations of particulate organic species are reported from residential indoor, residential outdoor, and ambient microenvironments from the TACS. Concentrations of particulate organic species are reported from three different compound classes: alkanes (C27 to C35), polycyclic aromatic hydrocarbons (PAHs), and hopanes. All samples were collected on Teflon filter media using Harvard Impactors (PM_2.5 size selection) which operated for 24 hours at 10 L/min (four consecutive days per subject). To increase analytical sensitivity for quantitation of these low volume samples, all samples were analyzed using a programmable temperature vaporization (PTV) injection gas chromatograph mass spectrometer (GC-MS). Preliminary data indicate that outdoor concentrations from all three chemical classes were typically at least a factor of two higher than indoor concentrations, suggesting the possible influence of mobile sources. As an example, average hopane concentrations from one study participant were 40.4 pg/m³ outdoors and 3.8 pg/m³ indoors. Results from all study participants and all compound classes will be presented. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Detailed Analysis of Soa Originating from the Photooxidation of D-Limonene in the Presence of No _x and UV Light and Its Implication to Ambient PM _2.5	10/20/2005

JAOUI, M., T. E. KLEINDIENST, M. LEWANDOWSKI, J. H. OFFENBERG, AND E. O. EDNEY. Detailed Analysis of Soa Originating from the Photooxidation of D-Limonene in the Presence of No _x and UV Light and Its Implication to Ambient PM _2.5. Presented at 24th Annual Conference of the American Association for Aerosol Research, Austin, TX, October 17 - 21, 2005.
Abstract:	A detailed analysis was carried out of the aerosol phase originated from the photooxidation of d-limonene in the presence of NO_x and artificial light with the analytical emphasis on the identification of oxygenated organic compounds. The major components included six tracer compounds including 3-isopropyl pentanedioic acid, 3-acetyl pentanedioic acid, 3-carboxy heptanedioic acid, C3-C6 linear diacids, ketolimonaldehyde, limonic acid, limononic acid. Two of the compounds were found to be tracers for d-limonene photooxidation in ambient filter samples.

PRESENTATION	Development of An Rh-Denuded Mie Active Sampling System and Targeted Aerosol Calibration	10/21/2005

RHODES, C., J. THORNBURG, J. SEAGRAVES, A. F. VETTE, AND R. W. WILLIAMS. Development of An Rh-Denuded Mie Active Sampling System and Targeted Aerosol Calibration. Presented at 2005 Detroit/Windsor Research Studies Meeting, Detroit, MI, October 21, 2005.
Abstract:	The MIE pDR 1200 nephelometer provides time resolved aerosol concentrations during personal and fixed-site sampling. Active (pumped) operation allows defining an upper PM_2.5 particle size, however, this dramatically increases the aerosol mass passing through the photometer optics. An examination of the potential calibration bias from internal soiling was needed. The factory MIE aerosol calibration relating photometer response to concentration is derived using poly-dispersed Arizona Test Dust (ATD). A more robust, targeted calibration using NH₄NO₃ at 5g/m³ levels instead of ATD in the mg/m³range was needed to better represent Detroit metro PM during the Detroit Exposure and Aerosol Research Study (DEARS) sampling. Another concern was limiting the operation of the MIE photometry to relative humidities RH's less than ~65%. An inlet humidity denuder was needed to limit the RH levels reaching the photometer, while minimally affecting aerosol transport. Addressing these issues was critical to the reduction in uncertainty when comparing MIE-obtained concentrations with DEARS gravimetric measurements. A new NH₄NO₃ laboratory calibration proved simple and cost-effective, and targeted a known PM_2.5 constituent of Detroit air, generated in much more realistic concentrations and size ranges relative to ambient particle loadings. Limited comparison of the MIE data against collocated gravimetric PM_2.5 sampling will be presented. It was determined that the ability to precisely set the internal MIE calibration potentiometers limited the attainable agreement against a referee measurement to 䔳%. A low transport loss silica gel inlet denuder was developed for both personal and fixed-location sampling. Humidity data from a HOBO downstream of the photometer, showed that the humidity denuder effectively maintained the RH between 40%-60% under field conditions. Silica gel dusting into the aerosol stream required a design change to stabilize the bed packing. Post-season MIE re-calibration showed no detectible influence from internal aerosol losses to the optics during 7 weeks of sampling. This was partially attributed to the PM_2.5scalping inlet. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Correcting Energy Expenditures for Fatigue and Excess Post-Exercise Oxygen Consumption	11/02/2005

ISAACS, K., G. GLEN, T. R. MCCURDY, AND L. SMITH. Correcting Energy Expenditures for Fatigue and Excess Post-Exercise Oxygen Consumption. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The EPA's human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the individual's current level of physical activity (PA), which is determined from activity diaries selected from the Consolidated Human Activity Database (CHAD). PA is quantified via standardized values of metabolic equivalent (METS) for the activity being performed. However, it is known that oxygen consumption may remain elevated after PA is completed. This effect, which is termed excess post-exercise oxygen consumption (EPOC), requires upward adjustment of the METS values of post-PA diary activities. In addition, since an individual's capacity for work will decrease during extended PA, methods are also required to adjust diary METS values that exceed physiologically-realistic limits over time. A unified algorithm for simultaneously performing these adjustments has been developed. The method simulates a cumulative oxygen deficit for each individual and uses it to impose appropriate time-dependent reductions in METS. The relationships between the oxygen deficit and the METS limits are non-linear and were derived from published data on work capacity and oxygen consumption. Simultaneously, post-PA METS values are augmented for EPOC. These adjustments were calculated from an analysis of the current EPOC literature. The algorithm was implemented in EPA's Air Pollutants Exposure Model (APEX). The method, which is flexible and computationally efficient, resulted in (1) appropriate multi-hour METS means and (2) improved physical activity index (PAI) distributions for children.

PRESENTATION	Physical Activity Index for Children: A Comparison of Literature Values and EPA's Chad	11/02/2005

SMITH, L., L. LIAO, K. ISAACS, T. R. MCCURDY, AND J. XUE. Physical Activity Index for Children: A Comparison of Literature Values and EPA's Chad. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The physical activity index (PAI) is a measure of an individual's energy expenditure level (and thus oxygen consumption) calculated as a time-weighted average of metabolic equivalents (METS) over the individual's activities. Many exposure models rely upon EPA's CHAD data base to obtain activity patterns. The object of this study was to compare PAI values reported in the literature to those calculated from CHAD. From the literature, 44 studies involving girls and 38 involving boys were used. From each study, the mean and standard deviation of PAI, sample size, and age were available. Ages ranged from 0 to 17. The summary statistics were averaged, weighted by sample size, to obtain a mean and standard deviation for each age-gender category. For these same categories, PAI values were calculated from CHAD, adjusting for both physiological limits and excess post-exercise oxygen consumption. Data were examined both graphically and via statistical hypothesis testing. The results indicate that CHAD yields higher PAI values than those reported in the literature for both genders across the range of ages. While variability of PAI was not significantly different between CHAD and the literature studies when tested across all ages, the results suggest that CHAD may give larger standard deviations for older children.

PRESENTATION	A New Method of Longitudinal Diary Assembly for Exposure Modeling	11/02/2005

GLEN, G., L. SMITH, K. ISAACS, T. R. MCCURDY, AND J. LANGSTAFF. A New Method of Longitudinal Diary Assembly for Exposure Modeling. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Many stochastic human exposure models require the construction of longitudinal time-activity diaries to evaluate the time sequence of concentrations encountered, and hence, the pollutant exposure for the simulated individuals. However, most of the available data on human activities are from cross-sectional surveys (usually one day per day). The variability of the population for long-term exposure is one property (among others) that depends on the method used to assemble activity diaries for long simulation periods (such as a year) from daily diaries. A new method, based on diary ranks with respect to a user-chosen key variable, has been developed targeting two statistics, D and A. The D statistic reflects the relative importance of within-person variance and between-person variance. The A statistic measures the lag-one (day-to-day) autocorrelation. The targets are met very closely for all simulation periods longer than 30 days, and reasonably well for shorter simulations. Longitudinal diary data from a field study suggest that D and A are stable over time (and perhaps over cohorts as well). The new method can be used with any cohort definitions and any day-type and season combinations, making it easily adaptable to most exposure models.

PRESENTATION	Coarse Particulate Matter Concentrations from Residential Outdoor Sites Associated With the North Carolina Asthma and Children's Environment Studies (Nc-Aces)	11/02/2005

CHEN, F., R. W. WILLIAMS, E. R. SVENDSEN, J. P. CREASON, J. W. SCOTT, D. TERRELL, M. W. CASE, AND K. YEATTS. Coarse Particulate Matter Concentrations from Residential Outdoor Sites Associated With the North Carolina Asthma and Children's Environment Studies (Nc-Aces). Presented at International Society for Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Coarse particulate matter (PM_10-2.5) concentration data from residential outdoor sites were collected using portable samplers as part of an exposure assessment for the North Carolina Asthma and Children's Environment Study (NC-ACES). PMcoarse values were estimated using the differential between the independent PM₁₀ and PM_2.5 collocated MiniVol measurements. Repeated daily 24-hr integrated PM₁₀ and PM_2.5 outdoor monitoring was performed at a total of 26 homes during 9/10/2003 to 6/10/2004. This effort resulted in the collection of 73 total daily measurements. This assessment was conducted to provide data needed to investigate the association of potential exposures to coarse particle PM mass concentrations with observed human health effects. Potential instrument bias between the differential MiniVol methodology and a dichotomous sampler were investigated. A Versatile Air Pollution Sampler and a cyclone inlet were also investigated in the overall comparison by placement of collocated instruments at a central ambient monitoring site. Correction for instrument bias ultimately allowed for a spatial comparison of outdoor residential coarse particle measurements across an area with a radius of 50 km to be performed as part of the NC-ACES . Results indicated that minimal bias (slope=0.97, intercept=0.35) existed between the dichotomous and differential MiniVol procedures. Residential outdoor PMcoarse mass concentrations were observed to be highly variable with respect across measurement days and range from 12.6 to 1.1 µg/m³ (mean of 5.39 µg/m³). The correlation between residential outdoor PMcoarse mass concentrations and those obtained from the central ambient monitoring site were typically greater than r =0.75. These results show that while PMcoarse mass concentrations were quite variable with respect to time they were relatively consistent in relation distances up to 50 km. Although this work was reviewed by EPA and approved for presentation, it may not necessarily reflect official Agency policy.

PRESENTATION	Determinants of Children's Pesticide Exposure in Yuma County, Arizona	11/02/2005

CHAPA, G., G. L. ROBERTSON, M. K. O'ROURKE, R. HART-MCELROY, R. SABOGAL, D. B. BARR, C. ROSALES, AND K. R. ROGERS. Determinants of Children's Pesticide Exposure in Yuma County, Arizona. Presented at International Society of Exposure Analysis, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	In 1999-2000, researchers from US EPA's Office of Research and Development in collaboration with several government and academic institutions conducted pesticide exposure assessment studies in Yuma county. Results from these studies have been previously reported (Gordon SM, et al J Expos Anal Environ Epidemiol 9 (1999) 456-470). One study was conducted in both urban and agricultural areas in Yuma county (Study 1). Urine samples were collected from 152 primary participants between four to seven years of age. Two additional studies limited to the agricultural intensive areas of Yuma county were conducted in two phases (Study 2, Stages 2 and 3). During phase one, 139 participants, ages two to six years, and 202 participants, ages one to four years, provided urine samples. House dust samples were also collected. Children with elevated dialkyl phosphate (DAP) urinary metabolites from each of the two studies (n=35-45) were selected to participate in the second phase consisting of a multi-media, multi-pathway exposure assessment. Questionnaire responses from each of the five studies regarding pesticide use, parental occupation, dietary ingestion, and children's activities were analyzed using non-parametric comparison tests. Relationships between responses to specific questions and both DAP urinary metabolite levels were examined to determine the factors that resulted in significant differences. Pesticide use inside the home contributed to a significant difference in ethyl urinary DAP metabolite levels for several studies. Differences in children?s urinary DAP metabolite levels based on children's activities, geographic location, and timing of sample collection will be presented. Linear regression models that explain the variability in methyl and ethyl DAP and TCPy (chlorpyrifos specific metabolite) levels are presented.

PRESENTATION	Perfluorinated Organic Compound Exposure Assessment Research	10/31/2005

LINDSTROM, A. B. AND M. J. STRYNAR. Perfluorinated Organic Compound Exposure Assessment Research. Presented at National Institute of Environmental Studies, Tsukuba, JAPAN, October 31, 2005.
Abstract:	A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this class that remain to be investigated. Many of PFCs (or their degradants) are persistent, bioaccumulative, and toxic to animal species. This presentation provides a general overview of this class of compounds and a summary of some of the PFC-related research underway at the US Environmental Protection Agency's National Exposure Research Laboratory. Gas and liquid chromatography/mass spectrometry methods have been developed for the most common perfluorinated alcohols, carboxylic acids and sulfonates. When applied to house dust samples, a wide range of PFCs was measured at ng /gram of dust level, concentrations which are very similar to those previously reported for residual pesticides in house dust. Overall, the house to house variability in these results suggests that there are a variety of potential residential sources of these materials, and that house dust may be an important PFC exposure route.

PRESENTATION	(China) Perfluorinated Organic Compound Exposure Assessment Research	11/05/2005

LINDSTROM, A. B. AND M. J. STRYNAR. (China) Perfluorinated Organic Compound Exposure Assessment Research. Presented at International Conference on Environmental and Genetical Damage, Chongqing, CHINA, November 03 - 06, 2005.
Abstract:	A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this class that remain to be investigated. Many of PFCs (or their degradants) are persistent, bioaccumulative, and toxic to animal species. This presentation provides a general overview of this class of compounds and a summary of some of the PFC-related research underway at the US Environmental Protection Agency's National Exposure Research Laboratory. Gas and liquid chromatography/mass spectrometry methods have been developed for the most common perfluorinated alcohols, carboxylic acids and sulfonates. When applied to house dust samples, a wide range of PFCs was measured at ng /gram of dust level, concentrations which are very similar to those previously reported for residual pesticides in house dust. Overall, the house to house variability in these results suggests that there are a variety of potential residential sources of these materials, and that house dust may be an important PFC exposure route.

PRESENTATION	Rapid Immunoassay and Bioanalytical Assessment Techniques for Determination of Organic Contaminants	12/14/2005

VAN EMON, J. M. AND K. R. ROGERS. Rapid Immunoassay and Bioanalytical Assessment Techniques for Determination of Organic Contaminants. Presented at BOSC Review, Cincinnati, OH, December 13 - 15, 2005.
Abstract:	This research demonstrates the feasibility of using an immunoassay method for dioxin and a toxicity screening assay for volatile VOCs.

PRESENTATION	Predictors of Exposure to 2,4-D for Farm Applicators in the Agricultural Health Study	11/02/2005

THOMAS, K. W., G. CHAPA, P. A. JONES, J. COBLE, M. DOSEMECI, C. W. CROGHAN, J. HOPPIN, AND M. ALAVANJA. Predictors of Exposure to 2,4-D for Farm Applicators in the Agricultural Health Study. Presented at International Society of Exposure Analyusis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The Agricultural Health Study is a large multi-agency epidemiological study of health in the agricultural community. A Pesticide Exposure Study was performed for a subset of AHS cohort members to measure exposures, assess exposure classification procedures, and examine exposure factors. This product reports the results of an analysis of occupational exposure factors for 2,4-D farm applicators in the AHS.

PRESENTATION	EXPOSURE MONITORING COMPONENT FOR DETROIT CHILDREN'S HEALTH STUDY ( DCHS )	10/21/2005

MUKERJEE, S. EXPOSURE MONITORING COMPONENT FOR DETROIT CHILDREN'S HEALTH STUDY ( DCHS ). Presented at Windsor/Detroit Studies Workshop, Detroit, MI, October 21, 2005.
Abstract:	Conventional, regulatory-based air monitoring is expensive and, thus, conducted at one or few locations in a city. This provides limited info on intra-urban variability and spatial distribution of air pollution. Research-oriented urban network monitoring has progressed with increased use of passive diffusion sampling and advances in sampler portability. Spatial analysis studies of ambient air pollutants have been conducted to assess traffic influence and its possible impact on respiratory health. This research has been enhanced by incorporation of ancillary variables from geographic and demographic sources to assess neighborhood differences of air pollution; approach has been termed land-use regression (LUR) modeling. The LUR modeling effort for the Detroit Children's Health Study will be discussed.

PRESENTATION	Reliability of Biomarkers of Pesticide Exposure Among Children and Adults in Ctepp Ohio	11/02/2005

EGEGHY, P. P., M. K. MORGAN, C. W. CROGHAN, AND Reliability of Biomarkers of Pesticide Exposure Among Children and Adults in Ctepp Ohio. Presented at International Society for Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Urinary biomarkers offer the potential for providing an efficient tool for exposure classification by reflecting the aggregate of all exposure routes. Substantial variability observed in urinary pesticide metabolite concentrations over short periods of time, however, has cast some doubt on their usefulness. Greater attention to the within- and between-person variation in biomarker concentrations can provide insight into the reliability of a single measurement in representing a longer-term mean, and can improve the effectiveness of measurement efforts. The reliability of urinary biomarkers of pesticide exposure was investigated in a subsample from the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study. A series of up to six spot urine samples (including first morning voids) collected over a 48-h monitoring period from 15 Ohio preschool children and their adult caregivers was analyzed by GC/MS for several biomarkers, including the non-specific pyrethroid metabolite 3-phenoxybenzoic acid (3-PBA) and the somewhat specific chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The Intraclass Correlation Coefficient (ICC), the ratio of the between-person component of variance to the total variance (sum of the within- and between-person components), was used to make inferences regarding the reliability of a single spot sample in representing a 48-h average. Measurements of 3-PBA from children were more reliable than those from adults, with ICCs of 0.69 and 0.52, respectively. Conversely, measurements of TCPy from children were less reliable than those from adults, with ICCs of 0.44 and 0.67, respectively. The ICCs for 3-PBA from children and TCPy from adults indicate good reliability, with a single measurement adequately representing the mean. Adjustment of values by specific gravity did not meaningfully change the ICCs. These results suggest that the consistency of urinary metabolite concentrations over relatively short periods of time may be dependent on both the metabolite and the study population.

PRESENTATION	An Enzyme Linked Immunosorbent Assay (ELISA) Method for the Urinary Biomonitoring of 2,4-Dichlorophrenocyacetic Acid (2,4-D)	11/02/2005

CHUANG, J. C., J. M. VAN EMON, J. DURNFORD, AND K. W. THOMAS. An Enzyme Linked Immunosorbent Assay (ELISA) Method for the Urinary Biomonitoring of 2,4-Dichlorophrenocyacetic Acid (2,4-D). Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	An enzyme-linked immunosorbent assay (ELISA) method was developed to quantitatively measure 2,4-dichlorophenoyacetic acid (2,4-D) in human urine. Samples were diluted (1:5) with phosphate-buffered saline, 0.05% Tween 20, with 0.02% sodium azide, and analyzed by a 96-microwekk plate immunoassay format. No clean up was required as a dilution step minimized sample interferences. Fifty urine samples were received without identifiers from a subset of pesticide applicators and their spouses in an EPA Pesticide Exposure Study (PES) and analyzed by the ELISA method and a conventional gas chromatography/mass spectrometry (GC/MS) procedure. For the GC/MS analysis, urine samples were extracted with acidic dichlorometane (DCM); methylated by diazomethane and fractionated by a Florisil solid phase extraction (SPE) column prior to GC/MS detection. The percent relative standard deviation (%RSD) of the 96-microwekk plate triplicate analyses ranged from 1.2 to 22% for the urine samples. Day-to-day variation of the assay results was within 120%. Quantitative recoveries of 2,4-D were obtained for the spiked urine samples by the ELISA method (>70%) as well as by the GC/MS procedure (>80%). The overall method precision of these samples was within 120% for both the ELISA and GC/MS methods. The estimated quantification limit for 2,4-D in urine was 30 ng/mL for the streamlined ELISA method. The ELISA and GC/MS data were highly correlated, with a correlation coefficient of 0.94 and a slope of 1.00. Results indicated that the ELISA method can be used as a high throughput, quantitative monitoring tool for human urine samples to identify individuals with exposure to 2,4-D above the typical background levels. The US EPA through its Office of Research and Development funded and managed the research described here under EPA Contract 68-D-99-011 to Battelle. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION	Secondary Organic Aerosol Formation from Mixtures of Biogenic Hydrocarbons	10/20/2005

OFFENBERG, J. H., T. KLEINDIENST, E. O. EDNEY, M. LEWANDOWSKI, AND M. JAOUI. Secondary Organic Aerosol Formation from Mixtures of Biogenic Hydrocarbons. Presented at American Association for Aerosol Research, Austin, TX, October 17 - 21, 2005.
Abstract:	In this work the influence of hydrocarbon mixtures on the overall Secondary Organic Aerosol yield is investigated. Photochemical reaction experiments were conducted using mixtures of a-pinene, isoprene and propene in the presence of NO_x. Results of the experiments showed the addition of a non-SOA forming hydrocarbon may increase the SOA yield of the SOA forming hydrocarbon by apparently increasing the reactivity of the mixture.

PRESENTATION	Analysis of Concordance of Probabilistic Aggregate Exposure Predictions With Observed Biomonitoring Results: An Example Using Ctepp Data	11/02/2005

SMITH, J. A., J. C. KISSEL, J. H. SHIRAI, M. K. MORGAN, L. S. SHELDON, AND C. W. CROGHAN. Analysis of Concordance of Probabilistic Aggregate Exposure Predictions With Observed Biomonitoring Results: An Example Using Ctepp Data. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Three key areas of scientific inquiry in the study of human exposure to environmental contaminants are 1) assessment of aggregate (i.e., multi-pathway, multi-route) exposures, 2) application of probabilistic methods to exposure prediction, and 3) the interpretation of biomarker measurements. An EPA-funded study has begun at the University of Washington that attempts to integrate these three areas of inquiry by simultaneous application to selected case studies. The project entails prediction of aggregate pesticide exposures using second order probabilistic methods, and comparison of those predictions to observed levels of urinary biomarkers using previously collected datasets. Concordance of predicted and observed results is evaluated following the methods of Lin and van Belle, which permit apportionment of overall deviance among accuracy, bias and scale. It is anticipated that insights gained will lead to improved model evaluation and, ultimately, improved exposure prediction. Demonstration of the overall approach is shown using chlorpyrifos (CP) exposure-related data from the U.S. EPA's Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) pilot study. The CTEPP study investigated the sources and routes of children's exposure to over 50 pollutants at their homes and daycares in selected North Carolina and Ohio counties in 2000-2001. Spot urine samples were collected from 257 children under 6 years of age over a 48-hr period. Urine samples were analyzed by gas chromatography/mass spectrometry for multiple compounds including 3,5,6-trichloro-2-pyridinol (TCPy), which is the specific urinary biomarker of exposure to chlorpyrifos in humans. TCPy is also the signature degradation product of chlorpyrifos in exposure media. Prior deterministic analysis of the North Carolina CTEPP data has suggested a shortfall of predicted exposure to CP and TCPy relative to observed excretion of TCPy. This finding, the relatively rich dataset collected, and the critical population involved render CTEPP an excellent case for application of a second order probabilistic approach and for quantitative evaluation of the performance of that approach. This project is supported in part by U.S. EPA via STAR Grant RD-83184401-0. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. JAS was also partially supported via CDC/NIOSH Training Grant T42/CCT010418-11.

PRESENTATION	Use of PBPK Modeling to Assess Cypermethrin Exposure in Young After a Residential Application	11/02/2005

TORNERO-VELEZ, R., N. S. TULVE, M. S. OKINO, AND C. C. DARY. Use of PBPK Modeling to Assess Cypermethrin Exposure in Young After a Residential Application. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	PBPK modeling was used to interpret exposure to cypermethrin among children in a small community of Jacksonville,FL. Sock loadings of cypermethin were used as a measure of exposure to cypermethrin. Urinary markers served as a measure of absorbed dose. In a comparison of presumptive dermal and oral exposure, a MonteCarlo sampling routine was employed with the model, and showed that the oral pathway was a far greater contributor to the absorbed dose. Additional data on residues in food comsumed by study participants (from duplicate diet assessment) indicated an apparent relationship with environmental loadings. Using the model, it was found that these residues result in urinary markers above NHANES 95% for chlorinated chrysanthemic metaboltie (DCVA) in the population suggesting that the residues are derived from home application, not from agricultural processes.

PRESENTATION	Air Toxics Modeling Research Program: An Overview	10/19/2005

HALL, E. Air Toxics Modeling Research Program: An Overview. Presented at EPA Region III Air Toxic Summit, Philadelphia, PA, October 18 - 20, 2005.
Abstract:	This product is a Microsoft Powerpoint slide presentation which was given at the joint EPA Region 3 - Mid-Atlantic Regional Air Management Association (MARAMA) Air Toxic Summit in Philadelphia, Pennsylvania held from October 18, 2005 through October 20, 2005. The slide presentation gave an overview of air toxics (computer) models used to assess population exposures to various hazardous air pollutants. A short history of exposure models was given that introduced the key features that exist in the current generation of exposure models. An overview of the Stochastic Human Exposure and Dose Simulation (SHEDS) model was presented. The SHEDS Model has four variants (Air Toxics, Particulate Matter [PM], Pesticides, Wood). Each variant of SHEDS is used to determine the variability and uncertainty associated with human exposure to hazardous substances. The SHEDS models take into account the major pathways of exposure (dietary ingestion, non-dietary ingestion, inhalation and dermal contact) along with the locations and activities of people as they are being exposed to various substances. The Consolidated Human Activity Database (CHAD) inputs human physiological and activity/location information into the SHEDS models to give realistic exposure and dose profiles for individuals and population groups."

PRESENTATION	Utilizing the Paks Method for Measuring Acrolein and Other Aldehydes in Dears	11/01/2005

HERRINGTON, J., J. ZHANG, L. ZHING, D. A. WHITAKER, R. W. WILLIAMS, AND C. RHODES. Utilizing the Paks Method for Measuring Acrolein and Other Aldehydes in Dears. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Acrolein is a hazardous air pollutant of high priority due to its high irritation potency and other potential adverse health effects. However, a reliable method is currently unavailable for measuring airborne acrolein at typical environmental levels. In the Detroit Exposure and Aerosol Research Study (DEARS), we employed a newly developed method to measure acrolein and the two most abundant aldehydes: formaldehyde and acetaldehyde. This method involves the collection of the aldehydes using the Passive Aldehydes and Ketones Sampler (PAKS) and the subsequent sample analysis using an HPLC-Fluorescence technique. The PAKS is a diffusion-driven sampler consisting of solid sorbent coated with dansylhydrazine (DNSH) that derivatizes aldehydes into fluorescence-generating compounds. Two versions of the PAKS method have been used in the DEARS so far. The version used during the first sampling season (July - August, 2004) was modified from the originally published PAKS method and had method collection efficiencies of ~100% for all three aldehydes. Results from the samples collected in the first season showed that this version of the method exhibited relatively high laboratory and field blank levels for formaldehyde and acetaldehyde. Thus, this version was further modified to minimize the laboratory and field blank levels. The method used during the second sampling season (February - March, 2005) did not exhibit high blank levels, but had slightly reduced collection efficiency for acrolein (85%). The sensitivity of the final method was demonstrated to be adequate for the 24-hour integrated sampling duration used in the DEARS. Based on the 24-hour sampling duration, the limits of detection (air concentration) were 0.96 (0.78), 0.75 (0.42), and 0.57 (0.25) µg/m³ (ppb) for formaldehyde, acetaldehyde, and acrolein, respectively. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	THE URBAN DISPERSION PROGRAM ( UDP ) NYC MSG05 EXPERIMENT	11/01/2005

LIOY, P. J., P. G. GEORGOPOULOS, D. A. VALLERO, J. DALOIA, G. J. FOLEY, J. N. BLANCATO, J. HEISER, M. REYNOLDS, AND P. KALB. THE URBAN DISPERSION PROGRAM ( UDP ) NYC MSG05 EXPERIMENT. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The multi-organizational Urban Dispersion Program (UDP) has been conducting tracer release experiments at various locations within the United States. In March 2005 the UDP conducted the first NYC based experiment called Madison Square Garden -05 (MSG05). The field study involved the release of six perfluorocarbon tracers (PFT) to the ambient air at designated locations around the Facility. The suite of tracers used at each site was different so that the influence of different emission sources at the PFT site can be differentiated. The general measurement program included stationary PFT monitors strategically placed at defined horizontal and vertical locations, and a complex array of meteorological equipment to measure near field and mesoscale wind speed, wind direction, etc. in the vertical and horizontal directions around the MSG. One of the four main goals of the UDP for New York City is "transferring improved capabilities for understanding the movement of contaminants to NYC emergency agencies." A component of the study being used to achieve this goal is having for the first time during an UDP a series of planned simultaneous prospective personal exposure measurements made on 12 individuals (i.e. EPA employees) during and after tracer release. The specific patterns of exposure selected for each personal monitor were designed to mimic the activities of EMS personnel, commuters, and other outdoor workers who could be expect to be present around the MSG facility during and after an accidental or deliberate release of a toxic agent. The discussion will present the design of the prospective exposure measurement program that is making use of personal monitors for PFT. In particular, the discussion will focus on how well the activities are being integrated into the overall UDP-MSG05 study. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Recruitment and Retention Activities Utilized During the First Two Seasons of the Dears	10/31/2005

PHILLIPS, M., K. EDGREN, C. RODES, D. AHSAN, A. F. VETTE, AND R. W. WILLIAMS. Recruitment and Retention Activities Utilized During the First Two Seasons of the Dears. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Identification, recruitment, enrollment, and retention of participants in the Detroit Exposure and Aerosol Research Study (DEARS) presented many challenges. A population-based cohort was chosen to reduce participant selection bias. Contact information for nearly everyone who lived in the five selected Census Tracts in the Detroit area of Wayne County, Michigan was purchased from a marketing vendor. The geographic coordinates for each home on the list were obtained in order to identify the homes either closest or farthest away from exposure sources (e.g. roadways and industrial point sources). Next, these houses were flagged in the datafile and systematic samples were randomly chosen and provided to the recruiters from the Community Action Against Asthma (CAAA) Group. A letter and DEARS study brochure were mailed to everyone on each list. Recruiters from CAAA performed door-to-door recruitment activities in the selected areas. To increase the likelihood of success, recruiters were hired from the community, trained by staff from the Research Triangle Institute and CAAA, and supervised by CAAA staff. Challenges faced in recruitment included: finding non-smokers; addressing language differences in situations where English was not the primary language spoken at home; overcoming a lack of trust regarding research among the largely low-income, minority population; demanding work schedules and other responsibilities; and lacking phone service among some participants. Although recruitment was a challenge, a total of 70 potential study participants were recruited from five exposure areas. Recruitment goals were achieved as only 40 participants were needed in the study allowing for several alternates in each area. Some of the participants dropped out of the study immediately prior to or during their week of sampling because they changed their mind about participating or a family emergency occurred. Participant dropouts caused difficulties because there were times when alternates were not available on such short notice. In these situations, CAAA recruiters performed additional door-to-door recruitment in order to fill the sampling schedule. Some of the study participants attended a retention-related gathering where they received recognition for their participation. After each season of data collection, participants were thanked for their participation by CAAA and EPA staff either in person or on the telephone. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Volatile Organic Compounds Measured in Dears Passive Samplers	10/31/2005

VETTE, A. F., W. A. MCCLENNY, D. A. WHITAKER, C. W. CROGHAN, C. D. STEVENS, C. RODES, K. OLIVER, H. JACUMIN, AND R. W. WILLIAMS. Volatile Organic Compounds Measured in Dears Passive Samplers. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	A suite of 27 volatile organic compounds (VOCs) were monitored in personal exposures, indoors and outdoors of participant's residences, and at a central community site during the DEARS summer 2004 monitoring season. The list of VOCs focused on compounds typically associated with mobile sources (1,3-butadiene, and BTEX - benzene, toluene, ethylbenzene, and xylenes) and those often associated with industrial or commercial sources such as chlorinated hydrocarbons and other halocarbons as well as other aromatic compounds. Passive diffusion samplers containing Carbopack-X (Supelco) were deployed on a daily basis to capture VOCs during a 24-hour sampling period. Observed BTEX concentrations revealed high temporal variability (std. dev. comparable to mean concentration). For example, personal exposures of benzene ranged from 0.6 to 14.0 ppbv (2.7 1 2.0 ppbv; mean 1 std. dev.); similar variations existed indoors and outdoors for benzene and for concentrations and exposures of toluene, ethylbenzene and xylenes. Levels of 1,3-butadiene were, on average, about two times higher indoors (0.6 1 0.3 ppbv) and in personal exposures (0.8 1 0.3 ppbv) than those measured outdoors (0.3 1 0.2 ppbv). Mean concentrations of BTEX and 1,3-butadiene followed the expected overall trend: personal > indoor > outdoor. There was considerable spatial variability in outdoor concentrations of BTEX and 1,3-butadiene with as much as seven-fold higher concentrations measured at residential outdoor sites as compared to a central community monitor. For most measurements, levels of BTEX and 1,3-butadiene were higher in areas with mobile source impacts. Concentrations of many of the chlorinated and fluorinated compounds were mostly below detection. Notable exceptions were compounds that are used in commercial products for personal care (trichlorofluoromethane), general household use (p-dichlorobenzene - mothballs), and other household products including vinyl flooring (styrene). Consequently, detectable levels of these compounds were mostly found indoors and in personal exposures and were not detected outdoors. Freon-113 levels were nearly uniform in all locations owing to its ubiquitous nature. Perchloroethylene, a solvent widely used for dry cleaning, was also measured in varying quantities, mostly indoors and in personal exposures. Data from winter 2005 monitoring will be presented along with initial source apportionment model results. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Use of Pharmacokinetic Models to Assess Occupational and Residential Pesticide Exposure	11/01/2005

OKINO, M. S., G. CHAPA, K. W. THOMAS, G. L. ROBERTSON, C. B. THOMPSON, A. TSANG, F. W. POWER, J. B. KNAAK, AND C. C. DARY. Use of Pharmacokinetic Models to Assess Occupational and Residential Pesticide Exposure. Presented at International Society for Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	Urinary biomarker measurements were analyzed using a dynamic pharmacokinetic model. The dynamic model provided the structure to link spot urine samples with corresponding exposure and absorbed dose. Data from both occupational and residential studies were analyzed. In the Agricultural Health Study/Pesticide Exposure Study, applicators who sprayed either 2,4-D or chlorpyrifos provided a composite urine sample for the 24-hour period following the day of application and a first-morning void three days following the event. Dermal exposure was assumed to occur over the period spent mixing, loading, and applying the chemical. Following the application event, a subset of participants also provided 24-hour urine samples for 5 consecutive days. The additional urine measurements provided a means to evaluate the dose estimates for the applicators. Some applicators conducted more than one application event during the 5-day urine collection period. For applicators without additional exposure events, the absorbed dose estimates calculated from spot urine samples were within a factor of 2 of the absorbed dose calculated from total urine collection. The scenario uncertainty and the difference compared to total urine collection were higher for applicators with confounding exposure events. The agreement within a factor of 2 for pesticide applicators without confounding exposure events provided a basis to apply a model-based analysis to residential settings, where spot urine samples were collected. Single spot urine samples were collected in studies of several populations along the U.S.-Mexico border and analyzed for pesticide urinary metabolites. Exposure scenarios were constructed based on questionnaire responses that indicate potential exposure events. Absorbed doses were calculated, and the dose uncertainty was characterized based on quantification of the uncertainty in the modeled exposure scenarios. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Exposures of Preschool Children to Pentachlorophenol, Bisphenol-a, and Nonylphenol at Home and Daycare	10/31/2005

WILSON, N. K., J. C. CHUANG, B. LORDO, M. K. MORGAN, AND L. S. SHELDON. Exposures of Preschool Children to Pentachlorophenol, Bisphenol-a, and Nonylphenol at Home and Daycare. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study investigated the potential exposures of 257 preschool children and their primary caregivers to >50 anthropogenic chemicals. This study was conducted in selected counties in North Carolina (NC) and Ohio (OH) in 2000-2001. Over a 48-h period in each child's daycare center and/or home, food, beverages, indoor/outdoor air, housedust, soil, transferable residues, food preparation surfaces, floor surfaces, and participants' hand surfaces and urine were sampled. Three phenols were among the measured chemicals: pentachlorophenol, bisphenol-A [2,2-bis(4-hydroxyphenyl)propane], and nonylphenol. Nonylphenol was detected in <10%, whereas pentachlorophenol and bisphenol-A were detected in !] 50% of the samples in several media. Pentachlorophenol was found in indoor air (97%), outdoor air (95%), dust (93%), and children's urine (89%) samples from NC; and in indoor air (88%), outdoor air (60%), dust (94%), soil (50%), and children's urine (99%) samples from OH. Bisphenol-A was found in indoor air (65%), hand wipe (94%), solid food (88%), and liquid food (79%) samples from NC; and in indoor air (65%), dust (51%), hand wipe (98%), solid food (100%), and liquid food (71%) samples from OH. In homes with recent pesticide applications, food preparation surface, floor surface, and transferable residue samples were also collected. Only bisphenol-A was detected in ≥ 50% of these additional samples of any medium: in floor wipe (81%), food preparation surface wipe (89%), and transferable residue (100%) samples from NC; and in floor wipe (96%), food preparation surface (85%), and transferable residue (71%) samples from OH. The children's potential pentachlorophenol exposures were predominantly through inhalation - pentachlorophenol was quantifiable in <6% of food samples, and in only 27% of hand wipes. In contrast, dietary ingestion accounted for almost all their bisphenol-A exposures (99%), with a minor contribution from inhalation (1%). Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Polycyclic Aromatic Hydrocarbon (PAH) Exposure of 257 Preschool Children	11/01/2005

CHUANG, J., N. K. WILSON, M. K. MORGAN, B. LORDO, Y. CHOU, AND L. S. SHELDON. Polycyclic Aromatic Hydrocarbon (PAH) Exposure of 257 Preschool Children. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	We investigated the polycyclic aromatic hydrocarbon (PAH) exposure of 257 preschool children and their adult caregivers in their everyday environments. Participants were recruited randomly from eligible homes and daycare centers within six North Carolina (NC) and six Ohio (OH) counties. Monitoring occurred over a 48-hour period at homes and daycare centers from 2000 to 2001. Environmental and personal samples were collected at both locations. Questionnaires and diaries were used to collect information on housing characteristics, products used in homes, and the activities of the participants. Target PAHs were frequently detected (>50%) in dust, soil, floor surface wipe, and transferable residue samples in both NC and OH, in NC air samples, and in OH hand wipe samples. Statistical analyses were performed to compare environmental measurements between home and daycare settings, urban and rural settings, and low-income and middle/high-income environments. Statistically significant findings included the following: (1) PAH loadings in floor dust (ng/m²) averaged higher (>500%) in daycare centers than in homes in both states, (2) PAH dust loadings and concentrations (ng/g) in OH averaged higher (>250%) in urban compared to rural settings, and (3) PAH indoor air and soil concentrations in NC averaged higher (>150% for air and >250% for soil) in low-income compared to middle/high-income environments. Potential exposure/absorbed dose estimates of PAHs for participants through the inhalation and indirect ingestion routes of exposure were also performed. Significant differences were observed primarily with indirect ingestion in OH children, with exposure/dose estimates averaging higher (>200%) for daycare children versus stay-at-home children and urban children versus rural children, and lower (~40%) for low-income versus middle/high-income children. Children were generally exposed to higher levels of PAHs than adults in the same household; this is likely due to different physiological factors (i.e., ventilation rates and body weights) and activity patterns among children and adults. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	( DETROIT, MI ) STUDY DESIGN AND PRELIMINARY EXPOSURE FINDINGS ASSOCIATED WITH THE DEARS	10/21/2005

WILLIAMS, R. W., A. F. VETTE, C. W. CROGHAN, C. D. STEVENS, D. A. WHITAKER, W. A. MCCLENNY, R. C. FORTMANN, L. S. SHELDON, A. W. REA, H. WILSON, C. RHODES, J. THORNBURG, K. EDGREN, AND M. HEINDORF. ( DETROIT, MI ) STUDY DESIGN AND PRELIMINARY EXPOSURE FINDINGS ASSOCIATED WITH THE DEARS. Presented at Detroit/Windsor Workshop, Detroit, MI, October 21, 2005.
Abstract:	The Detroit Exposure and Aerosol Research Study (DEARS) is a three-year field monitoring study initiated in 2004 that is designed to measure exposure and describe exposure relationships for air toxics, PM components, PM from specific sources, and criteria pollutants. Detroit, Michigan was considered the best candidate for this study because of its current and projected future non-attainment status for PM_2.5, the number of point and mobile source influences present, its geographic location, meteorology, ambient monitoring networks, potential state and local collaborations, and community-based partnerships. The DEARS will examine the spatial variability of PM_2.5 and its components to determine the suitability of conducting health outcome studies using a central site monitor in an urban area like Detroit where there are many point sources. Source apportionment techniques will be used to evaluate the relationship between PM and air toxics from specific sources. The DEARS is designed to examine and quantify the impact of local ambient sources on the relationship between central site monitors and exposures. Personal, residential indoor and residential outdoor monitoring for a variety of PM and air toxics will be performed. Survey information will be collected on household haracteristics, heating and air conditioning system operation, local ambient sources, indoor and personal sources, and time-activity patterns. Residences in seven ambient source-impacted areas (mobile sources, point sources, and a control) will be monitored for 5 days in each of 2 seasons (summer, winter). A total of 120 residences will be monitored over 3 years for a total of 1200 household-person/days. A Speciation Trends Network site, Allen Park, has been selected as the central site monitor for this study. A description of the study design and preliminary PM data will be presented here. Preliminary findings from the summer 2004 monitoring period indicate that personal PM_2.5 mass concentrations ranged from 3 to 125 µg/m³. Residential outdoor PM_2.5 mass concentrations were determined to be fairly uniform (~ 17 µg/m³) in source-impacted areas. Particle-bound ammonium nitrate concentrations (~ 1 µg/m³) were found to be less variable than elemental carbon (1 to 2 µg/m³). The latter might reflect the influence of local line sources within the various study areas. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	(Tucson) Study Design and Preliminary Exposure Findings Associated With the Dears	11/01/2005

WILLIAMS, R. W., A. F. VETTE, C. W. CROGHAN, C. D. STEVENS, D. A. WHITAKER, W. A. MCCLENNY, R. C. FORTMANN, L. S. SHELDON, A. W. REA, H. WILSON, C. RHODES, J. THORNBURG, K. EDGREN, AND M. HEINDORF. (Tucson) Study Design and Preliminary Exposure Findings Associated With the Dears. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.
Abstract:	The Detroit Exposure and Aerosol Research Study (DEARS) is a three-year field monitoring study initiated in 2004 that is designed to measure exposure and describe exposure relationships for air toxics, PM components, PM from specific sources, and criteria pollutants. Detroit, Michigan was considered the best candidate for this study because of its current and projected future non-attainment status for PM_2.5, the number of point and mobile source influences present, its geographic location, meteorology, ambient monitoring networks, potential state and local collaborations, and community-based partnerships. The DEARS will examine the spatial variability of PM_2.5 and its components to determine the suitability of conducting health outcome studies using a central site monitor in an urban area like Detroit where there are many point sources. Source apportionment techniques will be used to evaluate the relationship between PM and air toxics from specific sources. The DEARS is designed to examine and quantify the impact of local ambient sources on the relationship between central site monitors and exposures. Personal, residential indoor and residential outdoor monitoring for a variety of PM and air toxics will be performed. Survey information will be collected on household characteristics, heating and air conditioning system operation, local ambient sources, indoor and personal sources, and time-activity patterns. Residences in seven ambient source-impacted areas (mobile sources, point sources, and a control) will be monitored for 5 days in each of 2 seasons (summer, winter). A total of 120 residences will be monitored over 3 years for a total of 1200 household-person/days. A Speciation Trends Network site, Allen Park, has been selected as the central site monitor for this study. A description of the study design and preliminary PM data will be presented here. Preliminary findings from the summer 2004 monitoring period indicate that personal PM_2.5 mass concentrations ranged from 3 to 125 µg/m³. Residential outdoor PM_2.5 mass concentrations were determined to be fairly uniform (~ 17 µg/m³)in source-impacted areas. Particle-bound ammonium nitrate concentrations (~ 1 µg/m³) were found to be less variable than elemental carbon (1 to 2 µg/m³). The latter might reflect the influence of local line sources within the various study areas. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Suitability of Using in Vitro and Computationally Estimated Parameters in Simplified Pharmacokinetic Models	10/25/2005

OKINO, M. S., W. CHIU, M. V. EVANS, F. W. POWER, J. C. LIPSCOMB, R. TORNERO-VELEZ, C. C. DARY, J. N. BLANCATO, C. CHEN, AND L. S. BIRNBAUM. Suitability of Using in Vitro and Computationally Estimated Parameters in Simplified Pharmacokinetic Models. Presented at North American ISSX Meeting , Maui, HI, October 23 - 27, 2005.
Abstract:	A challenge in PBPK model development is estimating the parameters for absorption, distribution, metabolism, and excretion of the parent compound and metabolites of interest. One approach to reduce the number of parameters has been to simplify pharmacokinetic models by lumping physiologic compartments. However, the a priori estimation of critical parameters for PBPK models - such as partition coefficients and metabolic rate parameters - is an active area of research involving both in vitro systems and computational algorithms. We present a mathematical analysis of the lumped models compared to comprehensive physiologic descriptions. When a priori parameter estimates are incorporated into PBPK models, the lumping of compartments introduces errors in the metrics of interest, including for peak and integrated (area under the curve) measures. We explore a number of methods to minimize the errors and evaluate the suitability of incorporating the pathway-specific a priori data generated from in vitro or computational methods into simplified pharmacokinetic models. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Fy06 Ord Pilot Study: Determine Bioavailability and Bioaccessibility of Arsenic in Soil and Develop Arsenic Speciation Methods	11/15/2005

BRADHAM, K. D., S. L. HARPER, D. J. THOMAS, AND J. T. CREED. Fy06 Ord Pilot Study: Determine Bioavailability and Bioaccessibility of Arsenic in Soil and Develop Arsenic Speciation Methods. Presented at 2005 US EPA Technical Review Meeting, Safety Harbor, FL, November 14 - 18, 2005.
Abstract:	The product is a presentation requested by the organizers of the 2005 US EPA Bioavailability Technical Review Workgroup. It presents an overview, approaches (in-vivo & in-vitro), and logistics of the ORD pilot study on bioavailability of arsenic in soil. The overall project was drafted as a response for OSWER's call for proposals. The research is a collaboration between two NERL divisions, HEASD and MCEARD, and OSWER.

PRESENTATION	Source Apportionment of Seattle PM 2.5: A Comparison of Improve and Enhanced Stn Data Sets	11/19/2005

LARSON, T. V., E. KIM, AND G. A. NORRIS. Source Apportionment of Seattle PM 2.5: A Comparison of Improve and Enhanced Stn Data Sets. Presented at Annual American Association for Aerosol Research , Austin, TX, October 17 - 21, 2005.
Abstract:	Seattle, WA, STN and IMPROVE data sets with STN temperature resolved carbon peaks were analyzed with both the PMF and Unmix receptor models. In addition, the IMPROVE trace element data was combined with the major STN species to examine the role of IMPROVE metals. To compare the average source contribution estimates, a time series bootstrap method was developed for estimating confidence intervals in PMF. Results were compared across model algorithms for data sets with differing sampling and analytical procedures.

PRESENTATION	Quality Management Plan for the National Children's Study	11/29/2005

KANTOR, E. J., J. J. QUACKENBOSS, W. GALKE, AND D. MICHAEL. Quality Management Plan for the National Children's Study. Presented at National Children's Study Assembly Meeting, Washington, DC, November 29 - 30, 2005.
Abstract:	EPA has taken the lead, in consort with NIH, in developing the Quality Management Plan (QMP) for the National Children's Study (NCS); the QMP will delineate a systematic planning process for the implementation of the NCS. The QMP will state the goals and objectives of the NCS, the management structure, project schedules, resources, milestones, and requirements. The QMP will identify the type of data and information the study requires, how and where this information will be obtained, the study's design, boundaries and constraints. The QMP will describe the multidisciplinary effort for the NCS and identify all QA documents needed for its implementation. The QMP will identify the organizations and persons responsible for the development, implementation, oversight, and monitoring of the NCS quality assurance requirements. The Quality Management Plan for the NCS, which will serve as the "umbrella" quality assurance document under which individual project or institutional specific Quality Management Plans, Quality Assurance Project Plans (QAPP) and Standard Operating Procedures (SOP) will be developed and implemented. The NCS QMP will address how specific quality assurance (QA) and quality control (QC) activities will be coordinated, integrated, and monitored over the course of the 21+ year study. The QMP will cite and explain all individual QA documentation that is expected to be developed over the course of the NCS study, the timeline for its development, who is responsible for what, who reports to whom and what procedures will be in place to assure the successful implementation of the QAM and it subsequent component QMPs, QAPPs and SOPs. The specific roles, authorities, and responsibilities of the various Agencies and Offices involved with the NCS will be clearly delineated. This QMP will be based on EPA's Requirements for Quality Management Plans (QA/R-2) which can be found on the web at http://www.epa.gov/quality/qs-docs/r2-final.pdf. The QMP will document the NCS Management and Organization, addressing NCS quality systems overall policy, scope, applicability, and management responsibilities. The Quality System Components will be discussed on how the NCS will manages its quality system and define the primary responsibilities for managing and implementing each component of the system. Personnel Qualification and Training will be reviewed to document the procedures for assuring that all personnel performing work for the NCS have the necessary skills to effectively accomplish their work. Procedures for Procurement of Items and Services that directly affect the quality of NCS activities will be documented. Appropriate controls for quality-related Documents and Records determined to be important to the mission of the NCS will be discussed. The QMP will document how the NCS will ensure that Computer Hardware and Software will satisfy its requirements. The QMP will document the Planning of individual data collection activities within the NCS to ensure that data or information collected are of the needed and expected quality for their desired use. And finally the QMP will describe or reference the process(es), including the roles, responsibilities, and authorities of management and staff for Assessment and Response. The QMP will Document how the NCS will determine the suitability and effectiveness of the implemented quality system. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION	Public Health Air Surveillance Evaluation (Phase): Background and Air Quality Aspect	12/07/2005

DIMMICK, F. Public Health Air Surveillance Evaluation (Phase): Background and Air Quality Aspect. Presented at Discussion between EPA, NYSDOH and NYSDEC, Albany, NY, December 07, 2005.
Abstract:	NERL's Human Exposure and Atmospheric Sciences Division and other participants in the Public Health Air Surveillance Evaluation (PHASE) project will be discussing their results with the New York State Departments of Health and Environmental Conservation. The PHASE project is a collaboration between the EPA, CDC and the States of Maine, New York and Wisconsin. The objective of this collaboration is to develop, evaluate, and demonstrate the advantages and limitations of different methods of generating air quality characterization surveillance data that could be systematically and routinely available to link with public health surveillance data as part of the CDC's Environmental Public Health Tracking Network. EPA has provided air quality data for ozone and fine particles based on ambient air monitors, an application of the EPA/NOAA Community Multiscale Air Quality model, and statistically developed estimates.

PRESENTATION	Algorithms for Estimating Resting Metabolic Rate and Activity Specific Ventilation Rates for Use in Complex Exposure and Intake Dose Models	12/05/2005

GRAHAM, S. E., T. R. MCCURDY, AND K. SHARMA. Algorithms for Estimating Resting Metabolic Rate and Activity Specific Ventilation Rates for Use in Complex Exposure and Intake Dose Models. Presented at Society for Risk Analysis 2005 Annual Meeting, Orlando, FL, December 04 - 07, 2005.
Abstract:	This work summarizes advancements made that allow for better estimation of resting metabolic rate (RMR) and subsequent estimation of ventilation rates (i.e., total ventilation (V_E) and alveolar ventilation (V_A)) for individuals of both genders and all ages. RMR is used in conjunction with activity-specific relative estimates of the energy expended by individuals for each activity that they undertake. These two data are first translated into activity-specific VO₂ estimates and then into V_E and V_A. The RMR equations, along with new V_E and VA algorithms, become the basis for estimating dose rate received associated with exposure to environmental contaminants as simulated individuals go through their daily life. The coordination of these algorithms is critical to maintaining the time-series of exposure and provides a more realistic approach for estimating exposure and absorbed dose than done previously, particularly when considering simultaneous chemical exposure of different pollutant types.

PRESENTATION	Exposure Modeling Sheds	12/05/2005

BURKE, J. M. Exposure Modeling Sheds. Presented at Regional Air Toxics Risk Assessment Annual Meeting, Atlanta, GA, December 05, 2005.
Abstract:	This presentation provides a general overview of SHEDS model features, describes algorithms in the SHEDS-Air Toxics model that focus on mobile source exposures and multipathway exposures, and presents examples of results from application of the SHEDS-Air Toxics model to benzene in Houston.

PRESENTATION	Air Research in the National Exposure Research Laboratory	12/08/2005

VETTE, A. F. Air Research in the National Exposure Research Laboratory. Presented at Air Toxics Risk Assessment Workshop, Atlanta, GA, December 08, 2005.
Abstract:	This presentation provides a summary of the FY06 air research program in HEASD in the context of the overall program in NERL and ORD. Included in the presentation is an overview and initial results from the Detroit Exposure and Aerosol Research Study. This presentation is to inform risk assesors (OAQPS, EPA Regions, State and Locals) of the research in HEASD focused on air toxics.

PRESENTATION	The Detroit Exposure and Aerosol Research Study (Dears)	12/15/2005

WILLIAMS, R. W., A. F. VETTE, C. W. CROGHAN, C. D. STEVENS, D. A. WHITAKER, W. A. MCCLENNY, R. C. FORTMANN, L. S. SHELDON, A. W. REA, H. WILSON, C. RHODES, J. THORNBURG, K. EDGREN, AND M. HEINDORF. The Detroit Exposure and Aerosol Research Study (Dears). Presented at Research Triangle Institute International Lecture Series , Research Triangle Park, NC, December 15, 2005.
Abstract:	Field data collections for the Detroit Exposure and Aerosol Research Study (DEARS) have completed one-half of the planned study design. The DEARS is collecting personal, residential indoor, residential outdoor and central community monitoring data involving particulate matter, volatile organic compounds, carbonyls, criteria pollutant gases and other species. Data collection from the first half of the study have been completed. Preliminary findings provide indications that the DEARS study design will provide needed data in better understanding the agreement between sources impacting community monitoring sites in comparison to those measured at the personal or neighborhood level.

PRESENTATION	Human Biomonitoring to Link Environmental Exposure to Biologically Relevant Dose	12/15/2005

PLEIL, J. D. Human Biomonitoring to Link Environmental Exposure to Biologically Relevant Dose. Presented at ILSI/HESI Workshop, Research Triangle Park, NC, December 15, 2005.
Abstract:	The abstract and presentation on Human Biomonitoring to Link Environmental Exposure to Biologically Relevant Dose describes the use of biomarkers of exposure, biomarkers of current health state, and biomarker measurements. The abstract and presentation focuses on how biomarkers measured on different matrices (e.g. blood) can provided useful information when linked to simple classical pharmacokinetic models. A discussion on the use of dosimetry, biomonitoring, biological damping and reconstruction of previous exposure will also be presented.

PUBLISHED REPORT	Sheds-PM Stochastic Human Exposure and Dose Simulation for Particulate Matter: Users Guide EPA Sheds-PM 2.1	05/31/2005

BURKE, J. M. Sheds-PM Stochastic Human Exposure and Dose Simulation for Particulate Matter: Users Guide EPA Sheds-PM 2.1. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/065, 2005.
Abstract:	This document provides instructions and background information for users of the Stochastic Human Exposure and Dose Simulation for Particulate Matter (SHEDS-PM) model.

PUBLISHED REPORT	EPA Pmf 1.1 User's Guide	10/04/2005

EBERLY, S. I. EPA Pmf 1.1 User's Guide. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-06/166 (NTIS PB2007-103431), 2005.
Abstract:	This user's manual is designed to guide a user through the use of the software EPA PMF 1.1 for a receptor modeling application. The manual covers details about what the user should do to operate the software, but it intentionally does not include guidance on how to interpret the output, other than to provide indicators about how well the model fits the user-provided data.

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